Adds option "releaseToActivate".

+ Option "releaseToActivate" and sets it to "true" by default. This allows changing your mind while sliding the handle and prevent the activation in the last second by sliding the handle back instead of releasing it.

* Merges the two test files mobile-tests.js and ui-tests.js to tests.js because they were nearly equal. Added a hidden input in the HTML files of the tests to distinguish which test set to run.
Merge branch 'master' of https://github.com/j-ulrich/jquery-sliderbutton.git

Conflicts:
	README.md
	changelog.md
	package.json
	sliderbutton.jquery.json
	src/jquery.mobile.sliderbutton.css
	src/jquery.mobile.sliderbutton.js
	src/jquery.ui.sliderbutton.css
	src/jquery.ui.sliderbutton.js