In particular, the gitfo_read_file() routine can be used to slurp
the complete file contents into an gitfo_buf structure. The buffer
content will be allocated by malloc() and may be released by the
gitfo_free_buf() routine. The io buffer type can be initialised
on the stack with the GITFO_BUF_INIT macro.

Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>