[BUGFIX] Do not keep call actors around after they've sent an end event
[BUGFIX] Execute FreeSWITCH call components synchronously

Celluloid's task suspension will take care of ensuring the call actor is not blocked
[BUGFIX] Trim FreeSWITCH Output complete handling overhead

This doesn't need to go back out to the mailbox as it's entirely contained within the actor anyway
[CS] Only listen for EventSocket events we care about

Should cut down event volume a lot
[DOC] Changelog entries
Merge branch 'feature/fs_perf_tweak' into develop

Conflicts:
	CHANGELOG.md
	punchblock.gemspec