support mono backend of scriptcs (Roslyn is limited)

[den-run-ai]

currently roslyn does not support dynamic objects in C#. in scriptcs the workaround is to start it up with scriptcs -modules mono command-line arguments to use Mono compiler backend. This second backend should be added to ICSHARP.

[zabirauf]

Currently icsharp is using scriptcs backend, we might have to create the instances related to scriptcs with the correct parameters. But if mono has to be explicitly installed for it then I think it will not be a good idea as usually on windows people don't have mono installed.

[den-run-ai]

i think scriptcs comes bundled with all necessary DLLs for Mono backend to work out of box.

[den-run-ai]

scriptcs/scriptcs#1092