Implemented an example of ajax request

The server waits 2 sec before answering, it sends JSON
The client displays correctly the loading widget and then a dialog.
Changed the way css files are included

jQueryMobile requires to have the same imports in all the files. Only
ghome.less is now imported in the html files. It contains @import
directives to merge all the css/less files
Added the less compiler to node_modules. Compilation instructions are
included in ghome.less