Merged show{view,layer,image,imageref} into visualize.
Updated README for visualize.
Added an error message if visualize in invoked on unsupported class.
Removed BOOL casts.
Renamed a variable, fixed a typo.
Removed unnecessary parentheses.
Added object helpers for class checking.
Merge pull request #25 from antons/visualize

Merged show{view,layer,image,imageref} into visualize