Fixed issue #114 - There are still iOS 6 dispatch_get_current_queue warnings in GCDAsyncUdpSocket.m

Used the same approach as in ef08e460756b391dd2fdd78d3133b1403f7671e1
Include GCDAsyncUdpSocket.h as the first order of business.
Merge pull request #134 from booleancandy/feature/GCDAsyncUdpSocket-includefix

Include GCDAsyncUdpSocket.h as the first order of business.
Merge pull request #129 from mgratzer/master

Fixes the iOS6 dispatch_get_current_queue() warnings in GCDAsyncUdpSocket.m
Updated podspec
Merge branch 'master' of https://github.com/robbiehanson/CocoaAsyncSocket

# By Martin Gratzer (1) and others
# Via Robbie Hanson
* 'master' of https://github.com/robbiehanson/CocoaAsyncSocket:
  Updated podspec
  Include GCDAsyncUdpSocket.h as the first order of business.
  Fixed issue #114 - There are still iOS 6 dispatch_get_current_queue warnings in GCDAsyncUdpSocket.m
Added type cast to squelch compiler warning.