[Reviewer: Graeme] Craft logging Enhanced Node Troubleshooting 

Added PDLog infrastructure (definition in new header, craft_dcea.h) and PDLogs for http and sip.
I have to say I find the idea of using a GCC-specific #pragma to get rid of a warning on GCC rather ironic - given it will likely cause an unknown pragma warning when using any other compiler.  Is there really no better solution to this?