Added osrfLogGetLevel method, then applied

Added osrfLogGetLevel method, then applied
partial patch from Scott McKellar:

Whenever a declared identifier had two leading underscores, I
removed the first one, except for a few cases where I removed the
second one and kept the first one.

I moved the prototypes for the following functions to log.c, and
declared them static:

 osrfLogSetType
 _osrfLogDetail
 _osrfLogToFile
 _osrfLogSetXid

I declared the following variables static:

 _osrfLogType
 _osrfLogFacility
 _osrfLogActFacility
 _osrfLogFile
 _osrfLogAppname
 _osrfLogLevel
 _osrfLogActivityEnabled
 _osrfLogIsClient
 _osrfLogXid
 _osrfLogXidPfx

git-svn-id: svn://svn.open-ils.org/OpenSRF/trunk@954 9efc2488-bf62-4759-914b-345cdb29e865