Fully converted for browser and Node.js

Created KwsUploader to upload files

Grunt support exporting generated files

Using custom version of node-XMLHttpRequest with a special browser.js main file
that use native browser implementations

Renamed KwsContent to KwsContentPlayer, KwsUploader to KwsContentUploader and
WebRtcContent to KwsWebRtcContent, and include all of them on a Node.js package
and also a kwsContentApi namespace on the browser.

Source code hierarchy has been (partially) adapted to standard Node.js one (it
keep to put all the files on the project root instead of src/main/resources)

Registered as a Bower package (needs integration on the toolschain)

Change-Id: Ie6faf18b1a25a3433445cad40a7712e5b0b85d6b