Added the mission of this next branch of tcpping
Added some bugs that I found
Refactored out some pieces of libnet1

Pieces that got refactored:
- find_device no longer uses libnet1 (and no longer destroys the libnet1 stack)
- get_source_ip no longer uses libnet1
Fixed a bug where you couldn't ping by hostname
Fixed a bug where contexts were adding up
Reworked to eliminate warnings

Two were legitimate, and one was actually doing something stupid (though not
directly causing a bug in any case I can think of).
Updated with the latest and greatest bugs