[plasma-framework] /: Revert "Enabling C++11 flags for clang and gcc"

[Ivan Čukić]

> such a premise VS2012 has a very partial C++11 support, Android NDK uses
> gcc 4.6 by default (apparently you can upgrade that to 4.7 but we can't
> expect third parties to do it by default, means partial support in both
> cases), BB10 cross- compiler doesn't properly support C++11. We're not

The agreement before was to use the features available in gcc 4.5 - nothing 
newer to be required (for example by using a bit ugly but useful replacements 
like Q_NULLPTR and Q_DECL_OVERRIDE)

Cheers

-- 
Progress isn't made by early risers. It's made by lazy men trying to find
easier ways to do something.
  -- Robert Heinlein