Problem reported by Ted Zlatanov in:
http://lists.gnu.org/archive/html/emacs-devel/2014-12/msg01093.html
* build-aux/git-hooks/commit-msg (space, non_space, non_print):
New vars. Use them as approximations to POSIX bracket expressions,
on implementations like mawk that do not support POSIX regexps.
Problem reported by Michal Nazarewicz in Bug#19337.
* build-aux/git-hooks/commit-msg: Add "commit message" to
diagnostics. Distinguish better between tabs and other
unprintable chars in diagnostics. Don't complain if a prefix
"fixup! " or "squash! " makes a summary line too long.
This fixes a bug reported by Jan Djärv in:
http://lists.gnu.org/archive/html/emacs-devel/2014-12/msg00704.html
along with some other issues I noticed while testing with FreeBSD.
* build-aux/git-hooks/commit-msg: Prefer gawk if available.
Prefer en_US.UTF-8 to en_US.utf8, as it's more portable.
Work around bug in FreeBSD 9 awk, where /[[:cntrl:]]/ matches
ordinary text characters.
Be less tricky about quoting "'" in a shell script.
* autogen.sh: Install Git hooks, if using Git.
* build-aux/git-hooks/commit-msg, build-aux/git-hooks/pre-commit:
New files, which are Git hooks that check for portable file names, and
do some simple checks for commit message format.
