Fix tray title/tooltip issues on Mac OS X

- Fix `tooltip` option in `Tray` creation being used for `title`.
- Fix `title` option in in `Tray` resulting in the title being truncated.
- Fix setting `title` field in `Tray` resulting in the title being truncated.

NOTE: the fist time we set the title property we have to call `setTitle` twice
or it won't get the right dimensions.

FIX rogerwang/node-webkit#2796