add missing files to the tarball

These files are added:
from src/core/MonoDevelop.Ide:
gtkrc
gtkrc.win32
gtkrc.win32-vista
gtkrc.mac

the file src/core/MonoDevelop.Core/BuildVariables.cs.in

the projects:
tests\TestRunner\TestRunner.csproj
src\core\MonoDevelop.TextEditor.Tests\MonoDevelop.TextEditor.Tests.csproj
tests\Ide.Tests\Ide.Tests.csproj