Changed parameter callback signature.
Added __version__ attribute
Updated docs for upgrade information.
Added notes on callback changes to the docs
Added style helpers and added deeper ansi color support. Colorama now optional.
Added style and unstyle to docs.
Added tests for styling
Added note on dim.
Added secho
Added missing changelog entry.
Fix typo error in Merging Multi Commands example.

Possible typo error on the documentation example.
Added an edit function.
Added click.launch
Added changelog entry for click.launch
Added more examples to termui
Fixed a bug with click.edit and None as text.
Merge pull request #99 from jezenielzapanta/patch-1

Fix typo error in Merging Multi Commands example.
Merge pull request #98 from iKevinY/master

Adds retina display support to documentation
Customize required in arguments for nargs of -1
Added missing changelog entry.