Allow metadata keys to include digits, _, -.

Closes #328.
Don't read config for --help or --version

Also involves a refactor of options into those that make the program
quit immediately, and those that just alter the configuration.
Include the default.conf location in --help
Updated to use filestore 0.6 (new diff API).

Thanks to markwright for partial patch.
Version bump to 0.10.1.
Merge pull request #334 from benmachine/options

gitit.hs option improvements
Merge pull request #331 from ayamada/276233fd55f1e8f00ab2befb525b254bf6f9581a

supply $revision$ at _diff if "Changes from beginning to ..."
Merge pull request #330 from ayamada/0151c949500bbff68cc3a766af898588032a2476

duplicate unescaping to html-entity
Include format metadata in default installed pages.

This allows them to continue working when the user changes the
default page format.

Closes #329.
Added explicit path to Gitit User's Guide in default front page.
Fix Gitit User's Guide link on front page.

Previously it was broken due to "smart punctuation."
Fixed messages.

Now validation messages display again.
Switched from using lookRead to using looks for messages.

Closes #294.
Allow compilation against directory < 1.2 also.
Updated CHANGES.
Version bump to 0.10.1.1.
update cabal file, allow sha1-1.6.*
Merge pull request #335 from qnikst/master

allow sha1-1.6.*
Fixed regression in option parsing.

An earlier patch caused the '-f' option not to work.
Closes #336.
Version bump to 0.10.1.2.
Updated CHANGES.