Run Jenny server with optional configs, same as gen

[ethankennerly]

Thanks for supporting:
Jenny.exe gen Roslyn.properties

Would you have time to add this?
Jenny.exe server Roslyn.properties

Without this the ALT+CMD+G keyboard shortcuts don't work.

Or the editor freezes when pressing SHIFT+CMD+G.

Alternatively, would you have time to remove the reflection-based shortcut? Otherwise pressing SHIFT+CMD+G freezes the editor, as you mentioned in #476

Or move the tools menu and shortcut configuration out of a DLL and into a C# file so that the end-user can remove the broken commands?

[sschmid]

External generate will now send the selected properties path with client gen

You can select the desired properties with the new Switch Button.

Will be in the next release