+ comment some unclear requirements for master_eventq

+ remove the need for an snprintf in astman_get_header()
+ fix comment for manager list eventq
+ localize one variable and minor code simplifications.



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@45185 65c4cc65-6c06-0410-ace0-fbb531ad65f3