Revert "Use nullptr"

This reverts commit e3620ae8284cf1618a581f014ad8a35d0ff306f3.
Revert "Use some auto"

This reverts commit 47fa79d5e9b88a47fe3aeb250965c413ad6fb9d3.

Conflicts:
	Charm/Qocoa/qsearchfield_nonmac.cpp
	Core/CharmDataModel.cpp
Disable C++11 support

We want to support OS X 10.7, but the latest XCode/clang for OS X doesn't
have the initializer_list include that qlist.h unfortunately includes
in Qt 5.2.0 when C++11 is enabled. So until we drop the 10.7 requirement,
we cannot use C++11 together with Qt5.

Revert "Enable C++11".

This reverts commit eb68200cb48ce46abb60d3f2977a8bf4f72b8435.