Fix overlay regression that in some cases prevented injection into devices in myCreateDevice(/Ex)

Incorrect checking for element existence in the std::map using the operator[]
caused interfaces to be added to the device map that weren't actually injected
to yet.

To minimize code impact before DX11 branch merge replace correct existence
checks triggering the bug with checks on whether there's a valid handle
(!= NULL) present for that device in the map. This way the default constructed
(and hence NULL) elements caused by the use of the operator[] are harmless.

For the future we'll have to decide whether we accept additional elements for
"simpler" coding or use the "logically cleaner" style of using find and
iterators.
Fix warning due to implicit BOOL to bool conversion.
Fix bug and formating in subrosa PA plugin.
Fix various compiler warnings with VS2010