[Releasing] Including QOpenGLDebug in 5.1

[Giuseppe D'Angelo]

Howdy,

as per Lars' email, I'd like this set of classes to go in 5.1.
I will work today and in the next days to polish them and make sure 
they're in good shape (documented, tested) by March, 1st.

A WIP version is at https://codereview.qt-project.org/#change,48660 .

Any objections?

Thanks,
-- 
Giuseppe D'Angelo | giuseppe.dangelo at kdab.com | Software Engineer
KDAB (UK) Ltd., a KDAB Group company
Tel. UK +44-1738-450410, Sweden (HQ) +46-563-540090
KDAB - Qt Experts - Platform-independent software solutions