Small comment / formatting updates
Use conf_attr for configurable properties in koji module

Also small fix to remove uneeded accessor to conf_attr
in Git module
Add VersionChecker#should_check? helper and use
Split git modules out into polisher/git subdir

Simply code refactoring, no functional changes
Cleanup gem module

No major functional changes, though small update w/ internal
download mechanism to use shared curl handler instead of
instantiating one for each download
Remove extraneous curl.get
Cleanup / refactor rpm spec & requirement modules

No major functionality changes outside adding helper methods
which to simplify / componentize operations