extend `make clean` to catch more autogenerated artifacts
setup npm boilerplate to install `uglify-js` for development purposes
remove unused JS resources for the heatmap
update to mapbox.js 1.5.0 and latest markercluster library

also include versions in file names to make it easier to check for updates
in the future
avoid inline JS and refactor map_world to use a separate JS file
add a new `make js` command and use a combined js file for the maps page
remove unused `csv2geojson.min.js`
use new `base-combined.js`

also downgrade jQuery to 1.9.1 to avoid tabzilla compareVersion bug which lead
to extranous download of a jQuery 1.7.1 release in addition to our 1.10.2
move ga.js snippet into external file and combine it into base-combined.js

this is preparation work for enabling CSP