modules: updated FindCorrade.cmake.
Dropped GCC 4.6 support.
Removed superfluous template parameter from EnumSet typedefs.

Because with GCC 4.7 we can.
Using delegating constructors where apropriate.

Because on GCC 4.7 we can.
Use template aliases where possible.

Because with GCC 4.7 we can.
Added VectorTypeFor and MatrixTypeFor aliases to DimensionTraits.

Also a new gem we can use with GCC 4.7.
Use VectorTypeFor and MatrixTypeFor instead of DimensionTraits.

Much shorter lines. I like that.