Merge branch 'maint'

* maint:
Better advice on using topic branches for kernel development
Documentation: update implicit "--no-index" behavior in "git diff"
Documentation: expand 'git diff' SEE ALSO section
Documentation: diff can compare blobs
Documentation: gitrevisions is in section 7
shell portability: no "export VAR=VAL"
CodingGuidelines: reword parameter expansion section
Documentation: update-index: -z applies also to --index-info
Documentation: No argument of ALLOC_GROW should have side-effects

diff --cc Documentation/git-fast-import.txt
Simple merge

diff --cc Documentation/git-format-patch.txt
Simple merge

diff --cc git-am.sh
Simple merge

diff --cc t/t5560-http-backend-noserver.sh
Simple merge