* Started support for unaligned vectorization.

* Introduce a new highly optimized matrix-matrix product for large
  matrices. The code is still highly experimental and it is activated
  only if you define EIGEN_WIP_PRODUCT at compile time.
  Currently the third dimension of the product must be a factor of
  the packet size (x4 for floats) and the right handed side matrix
  must be column major.
  Moreover, currently c = a*b; actually computes c += a*b !!
  Therefore, the code is provided for experimentation purpose only !
  These limitations will be fixed soon or later to become the default
  product implementation.

Eigen/src/Core/util/Constants.h

@@ -45,6 +45,7 @@ const unsigned int NullLowerBit = 0x200;    ///< means the strictly triangular l
 const unsigned int NullUpperBit = 0x400;    ///< means the strictly triangular upper part is 0
 
 enum { Upper=NullLowerBit, Lower=NullUpperBit };
+enum { Aligned=0, UnAligned=1 };
 
 // list of flags that are lost by default
 const unsigned int DefaultLostFlagMask = ~(VectorizableBit | Like1DArrayBit | NullDiagBit | UnitDiagBit | NullLowerBit | NullUpperBit);