Update version in README, add Boost::program_options to dependencies.

README

@@ -1,7 +1,7 @@
 ############################################################
-          GnuCash 3.x README file.
+          GnuCash README file.
 
-The current stable series is GnuCash 3.x.
+The current stable series is GnuCash 4.x.
 ------------------------------------------------------------
 
 ##################
@@ -37,9 +37,7 @@ https://www.gnucash.org/download
 Dependencies
 ------------
 
-The following packages are required to be installed to run GnuCash:
-
-[see README.dependencies]
+Please see README.dependencies for current build dependencies.
 
 The optional online stock and currency price retrieval feature requires Perl.
 This is generally already installed on Gnu/Linux and *BSD, and MacOS.

README.dependencies

@@ -67,7 +67,8 @@ Libraries/Deps
   ICU                                           International Components for
                                                 Unicode
   boost                 1.67.0                  All headers plus date_time,
-                                                filesystem, locale, and
+                                                filesystem, locale,
+                                                program_options, and
                                                 regex libraries.
                                                 locale and regex libs must be
                                                 built with ICU support.