Merging the 'map' branch with master

[markiliffe]

These two commits add a map visualisation of the waterponts. #efdee02 integrates a Leaflet.js map, whereas #b222139 integrates the clustering.

[kynan]

@markiliffe I rewrote the branch to fix some issues, partly formatting, like tabs etc.

I don't quite understand why you're loading the Map on the home page via the Map nav button instead of just adding a separate route for it. In particular since you can't currently hide the map again. It also means we're pulling in a jQuery dependency for not much benefit imho. @dgorissen?

[dgorissen]

To summarise:

• added route & use server side templates instead of js
• use font awesome for the icons (prettier).
• added the code to allow for custom cluster icons / colors

Marker colours are not yet dynamic on the water point status as that info is not yet in the db. Once that info is in the db, this is trivial to change on the ui side.

[kynan]

@dgorissen Can we load those assets from CDN rather than including them in the repo?

[markiliffe]

We can, I’ll update the links as much as I can and document.

[kynan]

OK, that's all done now, I've rewritten the branch. @nicowe has also fixed the JS formatting.