reason:
when the *ceil value* is `0` and the *model value* is `0`, the `valueToOffset` function returns `NaN`.
And the *low handle* label has a litter poor display.
the `single.html` shows the problem

* add `'use strict'` declaration
* update some docs
* optimize line#L423
* update line#L243-L251's format
* add .editorConfig file whose config is based on current sourcefile

Remove unnecessary dependency

Add umd support. Extract template in its own file.

take the *html fragment* out of the js file, and use *grunt-angular-templates* and *grunt-replace* plugin to generate the templateCache and insert it into the js file

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>