release libtcpedit as a standalone library

[synfinatic]

Yes, there is already libnetdude, but it has a lot of dependencies and I find it's API overly complex. Also, libnetdude is merely a framework for writing packet editing plugins, it doesn't ship with a large library itself and it also has too many dependencies (glib, libpcapnav).

Requirements:

1. Use libtool
2. Improve API docs
3. Plugin extension language (Lua or other)