Merge pull request #35 from DaveAckley/master

Element type non-const; merge
Cleanup after merge, nearly done with save functionality
Tweak ElementRegistry Init, and UUID functions
ExternalConfig::Write registers and places atoms; therefore is working on a basic level
Tile geometry added to configuration files
GUI Checkboxes
Checkbox fixes
Added FileByteSource . Reading config files almost works, but dies on reading an identifier for some reason
Moved FileByteSource to sim/
Added atomic symbols for elements
New element palette size, removed included .inc files
Don't track element .inc files; More Toolbox rendering tweaks
More toolbox rendering tweaks for Atomic Symbols
Save with alpha codes; get loading mostly working
New toolbox layout
South anchor for toolbox panel
Beginnings of loading/saving Atom bits
Fixed ExternalConfig::RegisterElement to assign puuid correctly
Beginnings of GUI sliders
Beginnings of GUI sliders