New features: scaling, rotation and choosing the buttons position

[akreienbring]

Hi, I added various features and options. Please have a look :-)

[colesobotka]

This is great! please pull this in. I was working on creating a modified version for my purposes, but this addition makes scaling the image properly a breeze. A great addition without breaking previous implementations. Great Job @akreienbring

[colesobotka]

Actually I may have spoken too soon. Unfortunately, the scaling is incredibly slow on mobile devices. I speaking particularly for ios in this case.