Improvements to SimDictionary for when you have a large number of objects in the game.  Under light load (i.e. under 5000 objects) this code actually runs slower that the stock simdictionary.  When you exceed 5000 objects, the template class actually runs faster and more consistently.
Made fixes
More comments added, move #include
fixed capital T
Tweaks so I'm happy with it.

 * Change #define usage
 * Fix tabs
Use find instead of [] and call StringTable->insert less.
Fix persistent underwater effect.
Guard against null pointers and remove unnecessary include.
Merge pull request #1077 from BeamNG/fix_underwater

Fix persistent underwater effect.
Merge pull request #1020 from eightyeight/simdictionary-improvement

SimDictionary improvement