Remove "go" directory.

People know about "termbox-go", there is no need for it anymore.
Backport collect_terminfo.py from Go.

Frankly, collectkeys.py doesn't work anymore, due to some changes in the
python's ncurses library. The collect_terminfo.py from Go queries the required
info using one process per tget. It solves the issue with collectkeys.py.
Fix for broken \x escape sequences in C.
Remove a bunch of useless stuff.
Use waf-based build system instead of the old one.
Put zeros at the end of generated sequences.
Zero is not required at the end of funcs sequence.
Prefer terminfo database, use built-in DB as a fallback.

The patch contains a partial terminfo parser (it parses what termbox needs
only). And the new logic is to prefer terminfo when it's available. Otherwise
it falls back to the old small built-in database.
Typo, cdir should be used here in a function call, instead of dir.
Change short to int16_t, we're using C99 in other parts of the code anyway.
Replace memstream with bytebuffer.
Get rid of ringbuffer. Use bytebuffer instead.
Name things more consistently.
Use a smaller input buffer, now that it can grow automatically.
Get rid of FILE-based input completely, use FDs and syscalls.
Actually pretend that EAGAIN never happens. It shouldn't, really.
Get rid of double buffering in the main input reading function.
Fix a couple of input parsing bugs.
Get rid of unsigned ints in the code and API. Use plain int instead.
Merge all termbox code into a single C translation unit.

Well, actually there are two translation units, but only because utf8
functions are kind of pure and separate anyway. I would like to remove them,
but the demo uses them and in most cases the end user needs them. It is sad
that C standard library still doesn't have proper utf8 functions.