Add CONTRIBUTING.md

More info on this kind of file:
https://github.com/blog/1184-contributing-guidelines
Add "Use a feature branch" in checklist
Add section on how to move commits from dev to a new branch
Increase version in shared AssemblyInfo

This should have been fixed together with sha e50d9b258
These values get updated when building anyway.
Act created
skipped unimplemented specs
base method wrappers for actor dsl lifecycle with tests
Merge pull request #379 from HCanber/increase-version

Increase version in shared AssemblyInfo
Merge pull request #373 from HCanber/contributing-md-372

Add CONTRIBUTING.md
Merge pull request #370 from Horusiath/dev

Implementation of Actor DSL
Update projects to output xml files for Configuration=Release
Push symbols to server

-Upgraded to latest FAKE 3.4.1
-build.cmd can be started from anywhere
-Let FAKE's NuGetHelper and nuget.exe build symbols packages and let
them decide which files to pick (no pdb and src in normal packages)
by putting everything needed for both packages in workingDir
-packages are pushed in it's own target PublishNuget after all packages
have been created. Unfortunately FAKE's publishing of packages do not allow
different symbol and nuget upload url's and do not expose any helpers
for publishing a specific nuget file so I copied their code.