Added version information

Version is now displayed whenever ScriptCs is launched.
#132 Version flag as a command

Specifying -version or -v will output version information.
#132 Version flag as a command
issue #155, added default references & default namespaces
tests for #155
Merge remote-tracking branch 'upstream/dev' into dev
#132 adapted to the latest code

Execute now returns a CommandResult
Merge pull request #156 from filipw/issue155

added default references and namespaces
#132 Removing reference to ScriptExecuteCommand.cs

File appears to be removed.  Tried checking this in earlier and it
apparently failed.
Merge pull request #146 from Codatrix/dev

#132:  Added version information
Added Get<T> method to ScriptHost and tests. Introduced IScriptHostFactory and introduced it in several places in code and tests
Merge pull request #163 from glennblock/160

Added Get<T> method to ScriptHost and tests. Introduced IScriptHostFacto...
Fixes #164. PowerArg package updated.
#161 Passing an invalid command-line argument will show arguments help.
Fancy command-line arguments help.
Fixes #161 Error message added (with PowerArgs exception message parsing).
Merge branch 'issue161' into dev
Merge pull request #166 from denis-mentey/dev

Fixes #161 and #164.