Set the mode to viewonly after the error so that user can still
see the tiles downloaded from the server, but cannot interact
anymore before server administrator fixes the disk space.
Change-Id: If03f4fabe93458672a631c020d09dcebecbb955c
Don't include each third party script in a separate <script> tag,
rather have one single main.js file require'ing these different
scripts. Then `browserify' on main.js which bundles everything
into a single bundle.js containing all of the dependencies.
Also add these 3rd party scripts such as jquery, jquery-ui,
select2 etc. using npm, rather than manually downloading their
files from the internet. This should ease the process of managing
these front-end dependencies; upgrade process should be very easy
now.
