Added support for -jvm-debug option to activator.bat

I HAVE NOT TESTED THIS.

MERGE AT YOUR OWN RISK.

I don't have a Windows box handy to test it.
I don't know why I put `suspend=y`, I must have copied it accidentally, but it's been fixed since Activator 1.2.4:

https://github.com/typesafehub/activator/commit/a64fdc92f9200299188f9ada11d7b2376f270b04