ToDo List
=========
This program is not even alpha stage, so there are TONS of improvements, which most 
probably will not be done, or maybe yes, who knows. 

=========
exec:
	* Capture SIP messages using libpcap
		In online mode, we're spawning a ngrep process that is responsible
		to write the captured messages to stdout.
		If we dont use correct ngrep filters (like udp or port 5060), most
		probably sngrep will fail to parse.
		We could remove this thread and capture the packages ourself.

sip:
	* Change parsing functions for something more efficient (osip2?)
		Parsing with sscanf is not the best way, but the simplest. If
		we require to parse more headers in the future, it will start 
		to be worse and worse;
		
ui:
 	* Change panels initialization
		Right now, all panels are initializated at the same, because
		each panel can only be invoked once (it is not possible to have
		two call details panel right now)
		
	* Improve scrolling in all panels
		Don't redraw panels if it's not required... just keep them.
	
	* Show call duration and Finish status
		It would be great to show this two columns on main screean.
		First one can be calculated from the difference between first
		and last messages timestamps.
		The second one, depends on the messages in the callflow. But the
		idea is something like: BYE (Normal Clearing), CANCEL (Canceled),
		486 Busy Here (Busy), ...