Added a more detailed exception messages.

Added a more detailed exception when an UnknownScopeException is thrown.
Fixed InCallScope to
- support multiple factories over context preservation
- support property injection
Merge pull request #2 from marcoerni/master

InCallScope fix for multiple factories and property injection
Added support to push unstable nuget packages to nuget.org
Merge remote-tracking branch 'megakid/master'
Added more detailed exception message

Conflicts:
	src/Ninject.Extensions.NamedScope/NamedScopeExtensionMethods.cs
Updated common build script to allow to build prerelease and final versions on the build server