Updates the .gitignore.
Code style changes and cleanup.

- no space between - or + and the return type in methods
- initial brace on same line as statement/function/method
- sets the prefix and organization on the project
- uses a readonly property for windows’ titles
- removes an obsolete, unused _elementRef property from HAXElement; unclear what it was doing there at all
- tabs, not spaces
Adds an -isEqualToElement: method to HAXElement for type safety.
Adds parameter assertions to back up static analysis.
Uses dictionary literals.

Fixes #24.
Targets infer ARCHS.
Puts ARCHS back in so we can build with 4.6.3 still.
Adds __bridge to some casts of CFSTR().

kAX… strings are generally object-like macros expanding to a CFSTR(…) invocation. CFSTR() itself expands to a builtin when constant CF strings are enabled, and a function call (returning CFStringRef) when disabled.

It’s unclear whether the compiler knows that CFSTR(…) instances are guaranteed to have program lifetime, and therefore that the bridges are irrelevant, or whether it is instead applying some heuristic to the builtin, but for the time being I’ve added the (apparently unnecessary) __bridge to NSString * casts of these constants, for consistency.
Merge branch 'feature/tidying' into develop
Updates the readme with thank-yous and examples.

Fixes #22.