UIWebView no longer stubs out initWithFrame

Stubbing out initWithFrame leads to a whole host of issues including:
- crashes when reload and stopLoading are called
- the need to fake out all properties, including ones that we'd get for free
- the need to set up fake properties with values that are consistent with UIWebView's values

Allowing the UIWebView to actually *be* a UIWebView appears to solve all these problems
and does not introduce any new ones...