Implemented CLI to check that login2context mappings contains context identifier.

Usage:
checkloginmappings
-A,--adminuser <arg> Admin username. In case -a/--all is provided
master administrator's user name is required; else
the one for context administrator
-a,--all Required. The flag to signal that contexts shall
be processed. Hence option -c/--context is then
obsolete.
-c,--context <arg> Required. The context identifier
-h,--help Prints a help text
-l,--login <arg> The optional JMX login (if JMX has authentication
enabled)
-P,--adminpass <arg> Admin password. In case -a/--all is provided
master administrator's password is required; else
the one for context administrator
-p,--port <arg> The optional JMX port (default:9999)
-s,--password <arg> The optional JMX password (if JMX has
authentication enabled)