Move Makefile to script/ directory

It was confusing me otherwise, having the makefile and node_modules/ dir
in different places.
Bump browserify and hbsfy versions

hbsfy 0.1.4 in particular fixes a bug that used the wrong Handlebars
version to precompile templates, which, in conjunction with Handlebars
updates, apparently broke Pots.
Give Backbone an explicit reference to jQuery

This is a hack, but fixes an error that mysteriously appeared in Pots
without any of my code changing. Possibly I upgraded my globally
installed version of Browserify.

Anyway, the root problem is that Backbone is not CommonJS-aware, and
attempts to save a global reference to jQuery, which will only exist if
jQuery has been defined (not imported!) before Backbone.