On click, move the handle closest to the event

Fixes issue #101.

Draggable range

Add a rzSliderOnChange attribute. 

Fixes #94. It was because the click on the bar was not handled properly and the min and max handles were not switched when needed.

Fixes #74: Range Slider - No label if "Min" is the same as "Floor"

Set bower version to 0.1.22

Support clicks on bar

Initial minimum label visible when value equals floor value. (reverted from commit e2f46c4f)

Add the possibility to directly click on the slider bar to set the value. It is also possible to click and drag directly from the bar.

Add a rzSliderOnChange attribute. <rzslider rz-slider-model="priceSlider" rz-slider-on-change="onSliderChange()"></rzslider>

Fix for #59