Add new configuration options
Plumb new config options through to stateful proxy
ENUM lookup changes for tel URI and user=phone support
Add setter functions for options to be used in UT
Merge remote-tracking branch 'origin/sto382_em' into gdr_sto382

Conflicts:
	sprout/stateful_proxy.cpp
Finish UTs
Merge remote-tracking branch 'origin/sto382_em' into gdr_sto382

Conflicts:
	sprout/stateful_proxy.cpp
Fix up merge error
Some code markups after review
More code review markups
Final markups
Merge pull request #562 from Metaswitch/gdr_sto382

ENUM changes for sto382