documentation updates:

* add upgrade notes to changelog
* add topic/channel info to design doc (and slides link)
* add document describing basic patterns from blog post
* update protocol doc with missing commands MPUB and IDENTIFY
Merge pull request #111 from mreiferson/docs_111

doc updates
nsqadmin: fix issue where actions did not work without lookupd
nsqd: cleanup topic/channel deletion ordering issues
Merge pull request #98 from mreiferson/nsqadmin_98

nsqadmin: some operations only work w/ lookupd cmdline option
Merge pull request #101 from mreiferson/deletion_101

delete channel ordering issues
separate datetime-format from filename-format (update for consistency)
Merge pull request #115 from mreiferson/to_file_fix_115

fix nsq_to_file filename formatting
Add HTTP notifications of admin actions to nsqadmin

This commit creates a global notifications channel on which the new
AdminAction type is sent, and a goroutine that reads the actions and
sends them as json blobs to the endpoint specified on the cmd line.

Deferring work on an audit page or some such thing to a later date