add -Wundef to the --enable-dev-mode flags, so that mistyped macro names in...

add -Wundef to the --enable-dev-mode flags, so that mistyped macro names in #if expressions will be caught
convert various #if expressions to #ifdef for macros that may not be defined (and where the value is not important)
Note: two of these changes are in bison generated files which is going to be inconvenient when they are regenerated


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@55329 65c4cc65-6c06-0410-ace0-fbb531ad65f3