Copied content from http://wiki.qt.io/New_Features_in_Qt_5.7

 and
edited it.

Change-Id: I2ae7c7857dfe58d6a081fcb34ff51fcd601bbf9a
Reviewed-by: Topi Reiniö <topi.reinio@theqtcompany.com>
Reviewed-by: Martin Smith <martin.smith@theqtcompany.com>