Update to ARC
Harmonize coding style
Use dictionary literals
Remove unneed WebView extension

We no longer support versions of Mac OS X, where `setDrawsBackground:` is not available.

Also removed mention of 10.5+ in the help menu.
Remove redundant storage keyword for property
Do not use bool in .mm files

Also, change variable to camelCase.
Prefer Foundation data types (e.g., NSUIntger)
Make class method an instance method
Remove workaround for signatureWithObjCTypes:

This was exposed in 10.5.