Issue 6316: 	Improve usability of long (and wide) stack traces: file name on the left and other
Remove forgotten tracing
Improve warning message
Do not use instanceof (dosn't work cross global env)
Properly get function name
Implementing commands: debug and undebug
Move JSD2 related API from DebuggerClientObject to DebuggerLib
Merge remote-tracking branch 'origin/jsd2' into issue6291
 Issue 6316: 	Improve usability of long (and wide) stack traces
Implementation of monitor/unmonitor command line APIs (only stack frames are missing)
issue6291: dead-code deletion + precisions in comment about 54f95df
Merge remote-tracking branch 'origin/jsd2' into issue6291