Store config in git config, allow multiple projects
Move option parser to a separate method
Use argparse instead of optparse
Show short description before options, longer text after
Use /usr/bin/env instead of /usr/bin/python
Call functionality directly instead of using subprocess
Refactor hook install and uninstall code

On hook uninstall move original hook back into original place (if it
exists).

Add notes about original hook to readme.
Output a red message on SprintlyException
Raise uncaught fatal exception for stack trace

Also emit a red error message
Rearrange readme slightly
Move commit hook logic into main module
Move call to initialize to the constructor
Tweak comments
Refactor commit hook, new features

- Allow Sprint.ly's alternate ticket syntax (ticket:44, issue:44,
  item:44, bug:44 as well as #44)
- Enter no string at all to skip referencing an issue, rather than 0
- Allow multiple item numbers at the start of the commit message
- Change default template to put the reference at the end
- Configurable commit message template via git config
  sprintly.template and sprintly.itemkeyword