Update release notes for 0.19.0
Update release notes for 0.19.0

pombredanne/fabtools,badele/fabtools,davidcaste/fabtools,bitmonk/fabtools,AMOSoft/fabtools,fabtools/fabtools,wagigi/fabtools-python,ronnix/fabtools,prologic/fabtools,ahnjungho/fabtools,n0n0x/fabtools-python,sociateru/fabtools,hagai26/fabtools