Rename .hgignore to .gitignore
Enhance .gitignore to use more standard patterns

Source: GitHub for Windows
Standard patterns for Visual Studio and Windows
Add missing XML documentation

For test methods in base test classes.
Originally I left these out, but it provides good documentation, explaining what the test methods are for if the XML comments are there.
Modify sln to use standard NuGet packages dir

In older revisions, I switched to using \lib instead of \packages.  However, \packages is better for NuGet-specific packages and libraries and \lib can be reserved for non-NuGet libraries (of which for this project there currently are none).
Convert sln to use NuGet Package Restore

This also has the effect of moving the NuGet packages directory from root to the sln directory (under /src).
Remove root level \bin directory

Originally it was more convenient to copy all binaries from the various VS project bin folders to a root-level bin folder.  However, since this project is ultimately going to be packaged for NuGet, this is no longer necessary.
Rename Testing* project dirs to NUnitExtensions*

(Part of Testing > NUnitExtensions rename effort)
- Testing -> NUnitExtensions
- Testing.UnitTest -> NUnitExtensions.UnitTest
Path update by Visual Studio in dependant project

(Part of Testing > NUnitExtensions rename effort)
Renamed solution file

(Part of Testing > NUnitExtensions rename effort)
Renamed project files

(Part of Testing > NUnitExtensions rename effort)
Path update by Visual Studio in dependant project

(Part of Testing > NUnitExtensions rename effort)
Rename all symbols

(Part of Testing > NUnitExtensions rename effort)
TS.Testing symbols -> TS.NUnitExtensions
Fixed project reference names

(Part of Testing > NUnitExtensions rename effort)
Add MSBuildTasks package to solution via NuGet
Change Build.proj to prevent clean errors

Add recursive switch to Clean target in Build.proj to prevent 'directory not empty' errors in build output
Add root build.cmd script to call Build.proj

Created build launch script for the Build.proj file generated by the MSBuildTasks package
Depricate GlobalAssemblyInfo.cs file

Replace CommonAssemblyInfo.cs with the GlobalAssemblyInfo.cs file auto-generated by the AssemblyInfo task in the Build.proj file.
Add GlobalAssemblyInfo.cs file to .gitignore since its generated and does not need to be in source control.
The only side-effect is that when someone initially pulls down the code, they will need to run \build.cmd before they can compile in VS, since it will be looking for the generated file.
Introduce GlobalAssemblyInfo.proj input file

Modify Build.proj to import an optional GlobalAssemblyInfo.proj file, which provides all inputs for the AssemblyInfo task.
This provides a clean separation of the build logic from the build input.  This would potentially be valuable if I were to suggest some of my changes to the MSBuildTasks project (https://github.com/loresoft/msbuildtasks) in a pull request.
Modify Build.proj to run solution unit tests

Using the NUnit task from MSBuildTasks and using the NUnit tool path in the referenced NUnit NuGet package.
Add .gitattributes

As suggested by GitHub for Windows.
A side-effect is that all files get modified in the repository to only contain LF (vs. CRLF) line endings.