adding controls to ensure region size does not change and sliding stops when the sides are reached (#775)
adding controls to ensure region size does not change and sliding stops when the sides are reached (#775)

* adding controls to ensure region size does not change and sliding stops when the sides are reached

* fixing whitespace

* fixing whitespace

* set to return instead of changing delta to 0

agamemnus/wavesurfer.js,ffxsam/wavesurfer.js,ale-grosselle/wavesurfer.js,katspaugh/wavesurfer.js,ale-grosselle/wavesurfer.js,agamemnus/wavesurfer.js,ffxsam/wavesurfer.js,katspaugh/wavesurfer.js