Bug-2171: pcc-mock - logging level configuration

+ Default logging level is INFO
+ New optional command line parametter --log-level <LEVEL>
+ Varied level of log statement

-other minor fixes:
	+ SymbolicPathName contains ingress IP address too.
    	+ Fixed issue with ByteBuffer sometimes exceeding String size.

Change-Id: Id1ded1c75d2dfc173d88c8372d7ce7e621a19aab
Signed-off-by: Milos Fabian <milfabia@cisco.com>
(cherry picked from commit 3498eac61c0ce5792631be804de6cf238c07585c)