Using nullptr instead of Q_NULLPTR

[Sergio Martins]

Hi,


https://community.kde.org/Frameworks/Policies#Frameworks_compiler_requirements_and_C.2B.2B11 
states gcc 4.5 as the minimum version, meaning we can't use nullptr.

However, since some time now, kf5 libraries are full of nullptr (~400 
occurrences) and nobody noticed.

We can either:
- Bump the requirement to gcc 4.6 and allow nullptr
- Fix kf5 and s/nullptr/Q_NULLPTR


I prefer the first option, it's the way forward and if someone was using an old 
gcc he would have complained by now.


Btw, what are the c++98/c++11 requirements for applications ? I could only find 
the page for frameworks.


Regards,
--
Sérgio Martins