Added the ability to change and then reset the ios master volume

[shibbs]

This is a modification to the slider control library to allow you to set the phone's master volume, and then set it back if needed using the clever little slider hack over at - http://stackoverflow.com/questions/19218729/ios-7-mpmusicplayercontroller-volume-deprecated-how-to-change-device-volume-no/24993026#24993026

Some documenation stuff will need editing, but to use it just do the following : volumeSlider = plugins.volumeSlider; volumeSlider.createVolumeSlider(10, 350, 300, 30); // origin x, origin y, width, height volumeSlider.setVolumeSlider(1.0); //or w/e you want here, I was just maxing it out. volumeSlider.resetVolumeSlider();

[shibbs]

Updated our repository to also allow you to set the volume on an android device using @battlmonstr 's modifications to make it work for Android.