Backports modifications made by Sunblink.

[justonia]

Changes:

• Routines, when stopped explicitly, now throw a RoutineStoppedException so that the async method can do cleanup in a try/catch/finally
• Use of DEBUG changed to DEBUG_ROUTINES, so that dev builds don't do expensive logging.
• Call stack compression via HideInCallstack attribute, so stack traces on routines aren't massive in logs.
• Support for no-domain-reload enter playmode option by resetting statics correctly.

Unfortunately, some files show full changes due to space/tabs/win/mac file formatting stuff. And some files have bad indentation for the same reason. I'd suggest that we just run the entire repo source through a formatter to make it consistent.

[tomblind]

Can we fix the formatting in the pr before merging?

[justonia]

@tomblind Sure, wanted to check first with you.