Add a parameter to git_pkt_parse_line to tell it how much data you
have in your buffer. If the buffer is too short, it returns an error
saying so. Adapt the git transport to use this and fix the offset
calculation.
Add the GIT_ESHORTBUFFER error code.
This are the types I intend to use for pkt-line parsing and (later)
creation. git_pkt serves as a base pointer type and once you know what
type it is you can use the real one (command, tip list, etc.)
Signed-off-by: Carlos Martín Nieto <carlos@cmartin.tk>
