Convert message_router routes to ao2.  Add support for removal.

Review: https://reviewboard.asterisk.org/r/2591/


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@390698 f38db490-d61c-443f-a65b-d21fe96a405b
Split AGI manager events, to remove SubEvent field.

This moves them to stasis, in the process.

(closes issue ASTERISK-21470)
Review: https://reviewboard.asterisk.org/r/2587/


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@390701 f38db490-d61c-443f-a65b-d21fe96a405b