Refactor rpm modules into smaller mixins

Minimal changes to cleanup / consolidate syntax
Split up Polisher::Gem into mixins
Split Polisher::Gemfile into mixins
Split Polisher::Git::Package into mixins
Move various modules to polisher/util directory

Extracts conf_helpers from core into its own module
More Polisher::Upstream into adaptors dir
Move Polisher::VersionChecker into adaptors, split into modules

Modules are pulled in from version_checker subdir, each
representing a target to check
Move Polisher::HasVendoredDeps into mixins dir
Move Polisher::VersionedDependencies into mixins dir
Update git modules to pull in new paths
Update rpm modules to pull in new paths

Includes small styles fixes
Move Polisher::Koji to target directory, split into modules
Move Polisher::Bodhi to targets directory
Move Polisher::Errata to targets dir

Pulls Polisher::Errata::Build into its own module
Move Polisher::Fedora into targets directory
Move Polisher::Bugzilla into the targets directory
Move Polisher::Yum into the targets directory
Move Polisher Apt and Rhn stubs into targets directory
Cleanup few outstanding modules

- Removed gem_state, previously added to the gem directory

- Remove git.rb, uneeded

- adds targets.rb including all currently defined targets
Reorganize specs / split along module lines