Added the 'move' event to the Slider class.
corrections between Docs and Source
Fix "snap" to final value

Imported a idea from @csuwildcat 's PR #253
fixes #252
Fix slider steps

As reported in #1073 modulus operator `%` can return unexpected results.
This PR addresses that and corrects a bug that  didn't allowed to have
steps with decimals, ie only allowed integers.

Behavior before (`range [0, 5], steps 10` - decimal steps are ignored):
http://jsfiddle.net/2vTqr/2/
Corrected behavior (decimal steps are not ignored):
http://jsfiddle.net/2vTqr/3/
Specs for Slider.js

Added Specs for Slider.js, the same code as seen in this jsFiddle with
longer timeouts: http://jsfiddle.net/N4req/
Polish

Added @anutron's suggestions/corrections
Added HTML interactive specs
Removed (comented) Syn.JS specs because of IE9
Fix indentation
Merge: Slider.JS - bug fix and new event "move"

 - closes #1198, closes #1047, fixes #1095 , fixes #1073, fixes #252, fixes #1068

 - More detailed explanation in the PR: https://github.com/mootools/mootools-more/pull/1256