Remembers previous item types

Now remembers previous item rarity and item types when you reload.
Fixed a few CSS bugs.
Started implementing view presets. Eventually these will be named and
editable column + item-type matchups.
Formatting + Calculated Columns

Added some calculated columns. Formatted the two main js files. Fixed a
minor bug with negative stats.
Major refactoring + minor changes

Renamed a few files. (will mess up history)
Passed loader and item-parser through jshint.
Added missing map base types.
Pretty sure I broke lots of stuff! :D
Restructured file hierarchy