Backport of 0fb85917: Improved the contrast of the color of the text in the tooltip to make it stand out more.

Backport of 76667f32, a5fe74a8 and f97d5019: Added an option to select between hover and click to trigger the tooltips.

Backport of 9a584e7a: Changed readme to markdown format and updated it so it can be used to generate the project page.

Backport of 432d57fa: Use :first selector to avoid adding the tooltip multiple times for a single form element. This fixes a problem with FAPI checkboxes and radios form elements.

- Refactored JS, thanks to poetro.
- Added settings form.
- Works nice now.