Fixed Git URL in Java tutorials

Change-Id: I2389df7fd68acd55d09cf070e3d1d33b94a67e7d
Updated README

Change-Id: Iad19b4efb514c628686224b431dd88ca93fbb617
Renamed some name links in "Mastering Kurento" section

Change-Id: I3081e37f9cd30da080addb632659057553b317fd