addition of dynamic parkinglots feature

addition of dynamic parkinglots feature

This feature allows for parkinglots to be created dynamically within
the dialplan.  Thanks to all who were involved with getting this patch
written and tested!

(closes issue #15135)
Reported by: IgorG
Patches:
      features.dynamic_park.v3.diff uploaded by IgorG (license 20)
      2009090400_dynamicpark.diff.txt uploaded by mvanbaak (license 7)
      dynamic_parkinglot.diff uploaded by dvossel (license 671)
Tested by: eliel, IgorG, acunningham, mvanbaak, zktech

Review: https://reviewboard.asterisk.org/r/352/

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@247248 65c4cc65-6c06-0410-ace0-fbb531ad65f3