Added /nologo for all msbuild calls

Added CleanAll batch file
Added the now rhino-free service test to silverlight

desired version of Visual Studio.

- Added StatLight and Silverlight unit testing
- Added copies of all projects for Silverlight
- Integrated Silverlight unit tests in build

1. Refactoring of build to allow multiple target frameworks
2. Addition of multiple Silverlight versions
3. Renamed *_Silverlight2 configurations to *_Silverlight
4. Added batch files for each framework build (Build20, Build35, Build40)
5. Moved the package building into MSBuild tasks
6. BuildAll.bat now builds all packages in one build
7. Removed Generate*Package.bat batch files (replaced by BuildAll.bat)
8. Removed the ability to build with 3.5 MSBuild
9. Source is only generated with Release/2.0 build of ProtoGen
10. Removed unit testing proto files from packaging
11. Removed the remaining 'pause' statements from all batch files
12. RunBenchmarks target now builds with .NET 2.0 instead of 4.0
13. Benchmark arguments can now be specified with BenchmarkArgs parameter
14. ProtoBench now supports '/log:path' so console can still see progress
15. Updated PublishRelease.bat and *.nuspec for new build output
16. Updated ProtocolBuffers.Serialization.csproj to omit extensions for 2.0
17. Added NUnit console configurations for each .NET framework version

Renamed StartMessage(name) to WriteMessageStart(name) on XmlFormatWriter as this
was intended to be an overload that did not get renamed.

Added unit tests for mime-type services extension.