Build 45 released

This update took much longer than it should have, but I had a hard drive die (no data lost thankfully) and have been expecting our third child so game development has been a bit slower the last 2 weeks.

Changes this update:
- terrain mesh creation speed greatly increased. Before, this was 40 to 75% of the game load time, now it is more like 1%. Recreating a zone (when a block is added or removed) should take almost no time and shouldn't be noticeable.
- water is no longer solid and acts a bit more like a liquid. Player will float in water now. Water still doesn't flow yet and water cannot be removed.
- updated terrain texture so that all materials should look like something instead of being all white. The new ones are mostly placeholders as they look rather bad.
- fixed a number of bugs
- block placement algorithm changed to check collisions with face of block that player is looking at.
- fixed several dozen shading errors mostly with borders. Caves should now actually be really dark. There is still an issue with fog being applied too early.

Next update goals:
- more water fixes, like water flowing, elimination of some of the water graphical oddities. Test for when the camera is under water to draw a water filter over the scene
- add some water sounds
- add music
- work on gameplay