Merge branch 'jc/mailinfo' into next
* jc/mailinfo:
mailinfo: skip bogus UNIX From line inside body
tutorial-2: typofix in examples.
tutorial: add discussion of index file, object database
tutorial: expanded discussion of commit history
tutorial: replace "whatchanged" by "log"
NO_INET_NTOP and compat/inet_ntop.c for some systems (e.g. old Cygwin).
remove superflous "const"
checkdiff_consume: strtol parameter fix.
Elaborate on why ':' is a bad idea in a ref name.
Reference git-check-ref-format in git-branch.