Create .gitignore template for Sencha Touch 2.1.x html5 framework.

Create .gitignore template for Sencha Touch 2.1.x html5 framework. This .gitignore file is intended for use in projects generated using the Sencha Cmd command line tool.

The structure of a Sencha Touch 2.1.x project, generated by the Sencha Cmd tool is described here:

http://docs.sencha.com/touch/2-1/#!/guide/command_app