Separate requirements file for dev packages

Also turn python coverage on by default and update the docs.
Remove superfluous install line from travis script
Remove nose as a pypi dependency
Docs cleanup
Document required version of mongodb and how to install it
Merge pull request #307 from girder/separate-requirements

Separate requirements file for dev packages
Refactor rest.requireParams to support string param arg
Remove other refs to require.js for swagger build step
Adding the first pass at a Google Analytics plugin

This includes the backbone.analytics.js file as well as JS and Python style
tests. The server component of the plugin is only for validation of the plugin
setting.
Small comment fix about ga global.
Fixing group member widget routing.
Backend for file contents update
Frontend file model changes to support updating file contents
Increase js coverage threshold to force us to write js tests
Customize UploadWidget in web client to allow file content update
Update variable name to reflect change
Adding an event for hierarchy widget routing.
Adding analytics for hierarchy widget routing.
Updating jshint version.
Adding plugin documentation.