ok naddy

Problem reported by naddy. ok naddy

Both GOT_FETCH_PKTMAX and GOT_SEND_PKTMAX had the same value. Declare this value as GOT_PKT_MAX in got_lib_pkt.h instead.

Move functions and data structures which implement Git protocol features required for fetching and sending pack files to new files lib/gitproto.c and lib/got_lib_gitproto.h. This code was duplicated in got-fetch-pack and got-send-pack. No functional change.

The Git protocol uses a simple packet framing format. The got-fetch-pack and got-send-pack programs contained identical copies of functions to support this format. Move related functions to new file lib/pkt.c and link both programs against this common implementation. No functional change.

The tokenize_refline() function could end up reading past the end of the buffer if the refline is not terminated with whitespace or \0.

The my_capabilities pointer may remain NULL. Check for NULL before use.

Exposed by trying to run got clone -l against shithub.us over git:// found by abieber@

The Git server can apparently send duplicate ACK responses even though we do not enable the multi_ack capability. According to the Git protocol docs the server should only send ACKs after receiving 'done' from the client if multi_ack has been enabled. However, a duplicate ACK response can be triggered by running 'got fetch -a' in our fetch_update_tag test. This resulted in the following error: got-fetch-pack: unknown side-band received from server got: bad packet received

Same change as 16aeacf7088d, for subdirectories other than lib/