Cleanup

### Changes
* Renaming grunt.js to Gruntfile.js (grunt@0.4)
* Total overhaul of Gruntfile.js to actually work with grunt-0.4
 - Added missing tasks to package.json
 - Renamed and clean up config
 - Excluded non-functioning tests
 - Made all files pass linting
* Adding .gitignore with some basic exclusions
* Cleaning up npm package/tar:
 - Excluded Gruntfile.js
 - Excluded test/ dir
 - Removed grunt as a regular dependency

`npm pack` cleanup result:

### Before
package/package.json
package/README.md
package/grunt.js
package/bin/grunt-wrap
package/LICENSE-MIT
package/tasks/grunt-cp.js
package/test/gruntplugin-example_test.js

### After
package/package.json
package/README.md
package/bin/grunt-wrap
package/LICENSE-MIT
package/tasks/grunt-cp.js