​0.3.0 - UI improvements

I will have quite a bit of free time over the next couple of weeks, and really like this game concept so want to build on it. To facilitate that I had to redo some of the UI.

1. The "3D" objects that were used for factory and unit UI have been replaced by actual tooltips
2. The new tooltips have more user-friendly wording, and for the factories, the required resources are now fully shown instead of just showing the 1st missing resource
3. The UI for the selected units and objectives has been improved, and will work on more resolutions
4. As you play the game, each level is now timed from the start to launching the rocket.
5. The pause menu screen has been re-worked
   1. Placeholder buttons for the 3rd and 4th levels have been added to  the menu screen (expect them over the holidays)
   2. Music and Sound effects volume sliders have been added (technically, they existed in v0.1.0, but they were hidden until now)
   3. Hover over a level you already played to see your best score
   4. Custom button textures, game logo and layout have been added