GIT 0.99.7c

Contains the following post-0.99.7b fixes:

 - rsh.c string termination fix by H. Peter Anvin
 - further fetch fixes by Sergey Vlasov
 - diff-tree documentation by Robert Watson.
 - 'git diff --cached' synonymous to 'git diff --cached HEAD'.
 - subprocess.py licensing status clarification.

Signed-off-by: Junio C Hamano <junkio@cox.net>

1. a9ab586 Retire support for old environment variables. by Junio C Hamano · 20 years ago
2. c7c81b3 Fix ?: statements. by Jason Riedy · 20 years ago
3. 35c3c62 [PATCH] git_mkstemp() fix by Holger Eitzenberger · 20 years ago
4. f2db68e [PATCH] git: add git_mkstemp() by Holger Eitzenberger · 20 years ago
5. 26c8a53 Add "mkpath()" helper function by Linus Torvalds · 20 years ago