keep figuring out workarounds for build issues on various platforms, just go
ahead and remove what started all of this.  Two instances of ast_calloc have
been changed to calloc in pbx/ael/ael.y.

ast_copy_string isn't actually needed here because the only place it is used is
in ast_expr2f.c.  However, the utils Makefile already builds its own
ast_expr2f.o with -DSTANDALONE, which makes it use strncpy instead of
ast_copy_string.


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@24115 65c4cc65-6c06-0410-ace0-fbb531ad65f3