fixing requires

* lib/twig.rb required anything in lib/twig/ which broke as soon as vim
  put its backup files in there
* bin/twig's requires broke when executed directly from the project directory
make branch_list_headers understand style options
add header_style option
add cli flag and twigrc option
don't reject, select!
colorful help text
fixing tests
adding more tests for header-style option
restore ruby-1.8.7 compatibility
changing the header-style pattern
fixing tests
fixing help text
ignore color codes in help text width
fixing help text width for overly long words
Add `branch` as a reserved property name
Add author to `twig-help`
Add tab completion for `-b` and `--branch`
Add docs for enabling tab completion
Fix tab completion script comments
Add debug mode to `twig init-completion`