Adds info about waiting coros.
Crash if you fail to destruct a sindex token.

This makes a very common error that I was making (failing to destruct a
sindex write token) lead to a crash rather than a deadlock. Hopefully
this will save me some pain.
Fixes a segfault and deletes a sindex_write_token.
Merge branch 'jd_coro_waiting_info' into issue_727
Thread an interruptor through.
Adds coro print script. Also adds parents to coros.
Prints the parent parameter of the coros.
Makes coros order hierarchically.
Makes coros still show index.
Makes erase range work on sindexes in a different way.
Make erase range respect the interruptor.
Fix crash when interrupting erase ranges.
Adds erase range to sindex queue.

Also adds the ability for an erase range to delay releasing the
superblock.
Remove code that was added for debugging purposes.
Remove the coro script.
Don't use nonexistant method.
No extra consts. Make things compile under gcc.
Catch an interrupted_exc_t that was crashing things.
Update range logic for sindex erase range.

I think this is correct. I'm still not 100% sure.
Remove an offending space for style purposes.