Merge branch 'maint-1.7.11' into maint
* maint-1.7.11:
Almost 1.7.11.6
gitweb: URL-decode $my_url/$my_uri when stripping PATH_INFO
rebase -i: use full onto sha1 in reflog
sh-setup: protect from exported IFS
receive-pack: do not leak output from auto-gc to standard output
t/t5400: demonstrate breakage caused by informational message from prune
setup: clarify error messages for file/revisions ambiguity
send-email: improve RFC2047 quote parsing
fsck: detect null sha1 in tree entries
do not write null sha1s to on-disk index
diff: do not use null sha1 as a sentinel value