Add more customization options

[bettimms]

Hi,

It would be great to have the option of customizing the clock using images just like ClockView!
https://github.com/nacho4d/ClockView/

[werediver]

This may require architectural changes like separating cock core from the rendering layer. Such separation will allow the library to keep the current rendering code aside with new image-based one. It seems to be pretty much work.

I didn't use any other analog clock libraries out there, so I'm interested in any opinion and/or comparison. Is this library really good? 😄