Issue #87: Added log4j conf using INFO level.
Set the log path to mule-app-openhim-core.log
Minor edit; switch to removeProperty rather than set with null.
Changed logging levels on any messages that print the message body to
DEBUG (as these messages may contain patient health information)
Changed the interface logging message (full request path)
Merge branch 'logging' of https://github.com/jembi/openhim into develop

Conflicts:
	flows/interface.mflow
	src/main/app/interface.xml