Fixing an issue with the ORMMAReady-check in the mraid script, causing a...

Fixing an issue with the ORMMAReady-check in the mraid.js script, causing a javascript error due to improper checking for undefined values. This in turn leads to the 'else'-case never being reached, as the script exits with an exception before that.

Decreasing the rate of the ORMMAReady-checks from 20ms to 500ms, as this was causing a high CPU-load on mobile devices.

Adding a method to manually execute javascript on any advertisement, not only the mraid-compatible ones. This also enables getting the results of the call back to the caller, as is not currently possible with the delegate callbacks through the MRaidViewDelegate protocol.

Increasing the optimization level on the debug-scheme, as well as removing the 'ONLY_ACTIVE_ARCH' build flag, as it led to the library not running on certain devices.