Added an experimental implementation for the Promise pattern.
A few more tests.
typo
Merge branch 'master' into promise
Matchign copyright with other sources.
Merge branch 'master' into promise
Merge remote-tracking branch 'origin/master' into promise

Conflicts:
	tests/bootstrap.php
psr-4
Added executor argument.
Moved continuecallback-related tests to its own file.
Ensuring we're on 100% coverage again.
Merge branch 'master' into promise
Work in progress. running into some issues.
It works, but it shouldn't.
Ok.. happy with it.
Updated changelog.