Started work on adding marker clusters to the app

- the idea is you will be able to toggle from the heat map to markers
- added a toggle button on the map as well, it isn't functional yet
Merge branch 'develop' into feature-markerClusters
- merged changes to not rely on external files

Conflicts:
	bower.json
	html/index.html
Merge branch 'develop' into feature-markerClusters
Added web workers to chunk out the way clusters are loaded

- Not sure if this is the best way to do it. This is my first exposure
  to web workers
Enabled points to load whenver year changes

- did a lot of refactoring
- created layers up front and stopped adding/removing every
- hid the button toggle for now
Made header fixed and adjusted zoom control positioning
Changed min/max zoom levels

- a bounding box must be set as well
Cleaned up files after running jslint
Added "offense type" data to the dump
Added popup to markers to display the "offense type"
Created a new web worker to calc crime type totals, added underscore

- I thought I would use it for more, currently it's use is trivial
Added basic gitignore
Added crime totals to DOM which will become the legend

- added new bower dependency for Handlebars
Created a config object to store common values such as min/max zoom
Started to incorporate backbone into the project

- added Backbone as a bower dependency
Indented all declarations within MainApp object
Cleaned up some jslint warnings
Implemented the population of the model via backbone
Started work on adding a toggle button for map legend
Tweaked the UI for the legend and the modal for the crime points