Bug fixes and image updates

Catch more rare exceptions

Fix another off by one error and catch rare exception

Fix off by one error for the number of standard colors

Fix some threading issues

Don't migrate from documents directory to shared app group until iOS 8

Added option to save color settings and textures to a shared app container. Colors will migrate automatically if this option is enabled later or if the user upgrades from iOS 6.

A few small bug fixes for the bars on the wheel view

A few small bug fixes with the color wheel view