moved out static pre processor stuff to a util class, as it will be used by REPL. Later we may want to do it by inheritance, but for now it's good enough
added filepreprocessor to process #r and #load in REPL
fixed tests that wouldn't compile
added support for adding references during REPL runtime
adding REPL tests
fix typo
Adding outputting return values
Merge pull request #233 from glennblock/230

Adding REPL tests for #230
Merge branch 'dev' of https://github.com/scriptcs/scriptcs into 221
added REPL #load and #r tests, and refactored #load and #r check from ExecuteReplCommand to Repl Execute
scriptcs Chocolatey package should depend on the NuGet.CommandLine package
Cleaned up Main method
Disabled type and position in usage. Merge HelpCommand and InvalidCommand into ShowUsageCommand
Update CONTRIBUTING.md
Update CONTRIBUTING.md
Renamed DebugFlag and AllowPreReleaseFlag arguments
Merge pull request #235 from glennblock/232

Adding dumping return values in the REPL #232
Merge pull request #240 from jrusbatch/issues/239

Fixes #239: scriptcs Chocolatey package should depend on the NuGet.CommandLine package
Merge branch 'dev' of https://github.com/scriptcs/scriptcs into 221

Conflicts:
	src/ScriptCs.Engine.Roslyn/RoslynScriptEngine.cs
Merged in latest changes from dev