remove async flag for async tests. Now auto-detects sync/async.
fixed ev spec
added missing guard() on timer callback
renamed guard_called to test_is_async
renamed guard to async
Merge pull request #146 from Tieske/auto_detect_sync

remove async flag for async tests. Now auto-detects sync/async.
Merge branch 'master' of git://github.com/Olivine-Labs/busted