Update docs to reflect new upload and dot source of env var for std ps cmd

website/source/docs/provisioners/powershell.html.md

@@ -29,20 +29,21 @@ The example below is fully functional.
 ## Configuration Reference
 
 The reference of available configuration options is listed below. The only
-required element is either "inline" or "script". Every other option is optional.
+required element is either "inline" or "script". Every other option is
+optional.
 
 Exactly *one* of the following is required:
 
 -   `inline` (array of strings) - This is an array of commands to execute. The
-    commands are concatenated by newlines and turned into a single file, so they
-    are all executed within the same context. This allows you to change
+    commands are concatenated by newlines and turned into a single file, so
+    they are all executed within the same context. This allows you to change
     directories in one command and use something in the directory in the next
     and so on. Inline scripts are the easiest way to pull off simple tasks
     within the machine.
 
 -   `script` (string) - The path to a script to upload and execute in
-    the machine. This path can be absolute or relative. If it is relative, it is
-    relative to the working directory when Packer is executed.
+    the machine. This path can be absolute or relative. If it is relative, it
+    is relative to the working directory when Packer is executed.
 
 -   `scripts` (array of strings) - An array of scripts to execute. The scripts
     will be uploaded and executed in the order specified. Each script is
@@ -51,12 +52,12 @@ Exactly *one* of the following is required:
 
 Optional parameters:
 
--   `binary` (boolean) - If true, specifies that the script(s) are binary files,
-    and Packer should therefore not convert Windows line endings to Unix line
-    endings (if there are any). By default this is false.
+-   `binary` (boolean) - If true, specifies that the script(s) are binary
+    files, and Packer should therefore not convert Windows line endings to Unix
+    line endings (if there are any). By default this is false.
 
--   `elevated_execute_command` (string) - The command to use to execute the elevated
-    script. By default this is as follows:
+-   `elevated_execute_command` (string) - The command to use to execute the 
+    elevated script. By default this is as follows:
 
     ``` powershell
     powershell -executionpolicy bypass "& { if (Test-Path variable:global:ProgressPreference){$ProgressPreference='SilentlyContinue'};. {{.Vars}}; &'{{.Path}}'; exit $LastExitCode }"
@@ -65,32 +66,34 @@ Optional parameters:
     The value of this is treated as [configuration
     template](/docs/templates/engine.html). There are two
     available variables: `Path`, which is the path to the script to run, and
-    `Vars`, which is the location of a temp file containing the list of `environment_vars`, if configured.
+    `Vars`, which is the location of a temp file containing the list of
+    `environment_vars`, if configured.
 
 -   `environment_vars` (array of strings) - An array of key/value pairs to
     inject prior to the execute\_command. The format should be `key=value`.
-    Packer injects some environmental variables by default into the environment,
-    as well, which are covered in the section below.
+    Packer injects some environmental variables by default into the
+    environment, as well, which are covered in the section below.
 
 -   `execute_command` (string) - The command to use to execute the script. By
     default this is as follows:
 
     ``` powershell
-    powershell -executionpolicy bypass "& { if (Test-Path variable:global:ProgressPreference){$ProgressPreference='SilentlyContinue'};{{.Vars}}&'{{.Path}}';exit $LastExitCode }"
+    powershell -executionpolicy bypass "& { if (Test-Path variable:global:ProgressPreference){$ProgressPreference='SilentlyContinue'};. {{.Vars}}; &'{{.Path}}'; exit $LastExitCode }"
     ```
 
     The value of this is treated as [configuration
     template](/docs/templates/engine.html). There are two
     available variables: `Path`, which is the path to the script to run, and
-    `Vars`, which is the list of `environment_vars`, if configured.
+    `Vars`, which is the location of a temp file containing the list of
+    `environment_vars`, if configured.
 
 -   `elevated_user` and `elevated_password` (string) - If specified, the
     PowerShell script will be run with elevated privileges using the given
     Windows user.
 
 -   `remote_path` (string) - The path where the script will be uploaded to in
-    the machine. This defaults to "c:/Windows/Temp/script.ps1". This value must be a
-    writable location and any parent directories must already exist.
+    the machine. This defaults to "c:/Windows/Temp/script.ps1". This value must
+    be a writable location and any parent directories must already exist.
 
 -   `start_retry_timeout` (string) - The amount of time to attempt to *start*
     the remote process. By default this is "5m" or 5 minutes. This setting
@@ -111,9 +114,10 @@ commonly useful environmental variables:
     This is most useful when Packer is making multiple builds and you want to
     distinguish them slightly from a common provisioning script.
 
--   `PACKER_BUILDER_TYPE` is the type of the builder that was used to create the
-    machine that the script is running on. This is useful if you want to run
-    only certain parts of the script on systems built with certain builders.
+-   `PACKER_BUILDER_TYPE` is the type of the builder that was used to create
+    the machine that the script is running on. This is useful if you want to
+    run only certain parts of the script on systems built with certain
+    builders.
 
 -   `PACKER_HTTP_ADDR` If using a builder that provides an http server for file
     transfer (such as hyperv, parallels, qemu, virtualbox, and vmware), this