Identity data fixes, Cordova XHR fixes

Couple of things fixed in this request:

- The `SFIdentityData` interface has been changed to return `NSString` properties for the API URLs that aren't legitimate URLs (since they have '{version}' in the middle of them).
- Updated the hybrid functionality to fix some issues with Cordova and whitelisting.  We now reset the user agent string back to its original value, for requests that set it to not have the Cordova whitelist information on the end.  This primarily manifests when calling the auth web view (which may in turn be calling SSO login hosts that don't pass whitelist inspection).