Mostly update the version requirements (ie. VS2013), but also remove
comments about the shader compiler as that is not needed anymore since a
while.

Change-Id: I1fd93d0246ca768aa1035c8b05a30c5a5310553e
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@theqtcompany.com>
Reviewed-by: Andrew Knight <andrew.knight@intopalo.com>