Fix up various coding guidelines issues ...

 - handle memory allocation failures
 - add an ast_ prefix to a publicly exported function
 - put curly braces in the right places
 - add a bunch of spaces where they should be be used


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@89266 65c4cc65-6c06-0410-ace0-fbb531ad65f3