`#define` out water effect code for tiles that are entirely land.

`SHOW_REFLECTIVE_OCEAN` and `SHOW_OCEAN_WAVES` have moved into the `GlobeSurfaceShaderSet` so they can vary on a per-tile basis, rather than being set identically for all tiles.  Tiles that are entirely land now use `undefined` for their water mask texture instead of a shared "land" texture.
Cleanup now that shader defines are managed elsewhere.
Merge pull request #2261 from AnalyticalGraphicsInc/optimizeLandTiles

`#define` out water effect code for tiles that are entirely land.