Mention that commit ids must be at least 4 chars.
Remove commands that are no longer supported.
Some tweaks to command summaries.
POD edits.
Update revert command to match git-based API.
The log command no longer takes a commit option.

Eventually, I plan to expand this command to support
all kinds of filters, such as commit, date, author, etc.

See `git log --help` for some of the possibilities.
POD edits.
Add support for nocolor to log command.