GnuGetText.pas with support for TWideStrings properties

The current version of GnuGetText for Delphi and C++ Builder does not support properties of type TWideStrings. Since I needed this (FastReport uses them for storing the report memos), I have added that feature. The new unit is in the subversion repository on SourceForge.

Be warned: I have only tested it with Delphi 2007. If you find a problem with it, please let me know.