Entries: Added assert.async. Deprecated start, stop, and asyncTest

Fixes #79
Fixes #74
Fixes #73
Fixes #72

Closes #82
This sounds weird. It makes sense after reading it three times, but I think we can do better. Especially the "request a resolution" throws me off. Longdesc uses the same terms, so my issue applies there as well.

Maybe look at grunt `async()` docs for some inspiration?