removed a few stray 'VirtualBox' term uses in comments and docs.

builder/qemu/artifact.go

@@ -5,7 +5,7 @@ import (
 	"os"
 )
 
-// Artifact is the result of running the VirtualBox builder, namely a set
+// Artifact is the result of running the Qemu builder, namely a set
 // of files associated with the resulting machine.
 type Artifact struct {
 	dir string

builder/qemu/driver.go

@@ -14,7 +14,7 @@ import (
 
 type DriverCancelCallback func(state multistep.StateBag) bool
 
-// A driver is able to talk to VirtualBox and perform certain
+// A driver is able to talk to qemu-system-x86_64 and perform certain
 // operations with it.
 type Driver interface {
 	// Initializes the driver with the given values:
@@ -29,7 +29,7 @@ type Driver interface {
 	Stop(string) error
 
 	// SuppressMessages should do what needs to be done in order to
-	// suppress any annoying popups from VirtualBox.
+	// suppress any annoying popups, if any.
 	SuppressMessages() error
 
 	// Qemu executes the given command via qemu-system-x86_64
@@ -50,7 +50,7 @@ type Driver interface {
 	// this will return an error.
 	Verify() error
 
-	// Version reads the version of VirtualBox that is installed.
+	// Version reads the version of Qemu that is installed.
 	Version() (string, error)
 }
 

website/source/docs/builders/qemu.html.markdown

@@ -194,10 +194,9 @@ Optional:
   This may have a value of either "kvm" or "xen" and you must have that
   support in on the machine on which you run the builder.
 
-* `headless` (bool) - Packer defaults to building VirtualBox
-  virtual machines by launching a GUI that shows the console of the
-  machine being built. When this value is set to true, the machine will
-  start without a console.
+* `headless` (bool) - Packer defaults to building virtual machines by
+  launching a GUI that shows the console of the machine being built.
+  When this value is set to true, the machine will start without a console.
 
 * `http_directory` (string) - Path to a directory to serve using an HTTP
   server. The files in this directory will be available over HTTP that will