Allow user programme to set RMR verbosity level

This change centralises the writing of messages to the standard
error device which allows the user programme to have control over
the verbosity level.  Introduces the new rmr_set_vlevel() function.

Signed-off-by: E. Scott Daniels <daniels@research.att.com>
Change-Id: I0c4b4b3af94d34b480622ec1f65a9da65cabf2b5
37 files changed