Add a first version of a new tab 'config.xml utility'

Will have controls to work with the config.xml more directly and easier than
it's done in the current page that only shows a list of links.
The entire skeleton for this new tab was added, but nothing was really implemented
yet in the javascript.
Includes a lot of changes especially in the views to organize them better.

refs #1110

Conflicts:
	src/api_mate.jade
Improve 'cake watch' a lot by using chokidar

Detects file changes a lot faster and now watches for anything inside src/,
not only the restricted list of files we were watching before.
Improve the header and add a footer
Reorganize and make the code more modular

Specially the js class, that is now more independent from the html markup than
it was before. It now expects certain "data" attributes in the html to find the
elements it needs, instead of expecting ids.
The goal is to have a js class that can be used in other environments and not
only in this application. This is the first step toward this goal.
Disable the tab config-xml temporarily

A lot changed in this branch, will merge it to master. But the config-xml tab
is not implemented yet. Disabling it for now, it can be reactivated once it is
properly implemented.