hard-dep for Qt 4.8

[Thomas Zander]

On Wednesday 18 January 2012 10.11.58 todd rme wrote:
> But according to Martin, this isn't just about API changes, it is also about
> behavior changes.  How do you expect people to know if they are relying on a
> Qt 4.8-specific behavior?

As far as I know there are no forward incompatible behavior changes between
Qt4.7 and Qt 4.8
I.e. AFAIK programming for 4.8 using 4.7 APIs but 4.8 behavior will give the 
same behavior on 4.7.