Strong name removal from plugins.

Plugins should not be referenced from any project, only among themselves.
Since latest version of plugin is always preferrable and they are xcopied instead of placed into GAC,
strong naming should be removed.

Removed references to rest cache project - this currently causes problems in Mono since not all dlls are copied to output path.

TODO: add script in Monodevelop for copying plugins dll to output path.
Revenj.Core project.

For using Revenj as standalone library (inside ASP.NET MVC for example),
only few dependencies are required.

Provide Revenj.Core.dll as entry point with requirements for additional dependencies (such as database persistence plugins.

Plugins configuration extended with assemblies property.
By default instead of scaning folder, use only core libraries available in App domain as plugins.
While this is not ideal for extensibility, if one wishes to use all kind of libraries, it can use Revenj server projects,
or change the code.
This is mostly zero configuration entry point.
Merge branch 'master' of git@github.com:ngs-doo/revenj.git

Conflicts:
	Code/Server/Revenj.Http/Revenj.Http.Mono.csproj