Add suspend=y support to jvm debug

[dwijnand]

This allows attaching a debugger to debug an early part of a program (instead of trying to race the JVM..).

@paulp I'm not sure how to implement this, basically add another flag or parse the -jvm-debug argument differently.. Do you have any suggestions, please?

[paulp]

-jvm-debug could be expressed as
-J-Xdebug -J-Xrunjdwp:transport=dt_socket,server=y,suspend=n,address= and I'm pretty skeptical about adding more aliases, especially since this very ticket demonstrates the problem with bundling options and I think debugger attachers are a small minority of overall users. You could add a documentation page with example startup invocations which cover this case.

[paulp]

(Or to the script itself, e.g. sbt -examples)

[dwijnand]

Ok, no worries. :-)