- add _packetCoeff() to Inverse, allowing vectorization.

- let Inverse take template parameter MatrixType instead
  of ExpressionType, in order to reduce executable code size
  when taking inverses of xpr's.
- introduce ei_corrected_matrix_flags : the flags template
  parameter to the Matrix class is only a suggestion. This
  is also useful in ei_eval.

Eigen/src/Core/util/ForwardDeclarations.h

@@ -30,7 +30,7 @@ template<typename Lhs, typename Rhs> struct ei_product_eval_mode;
 template<typename T> struct NumTraits;
 
 template<typename _Scalar, int _Rows, int _Cols,
-         unsigned int _Flags = EIGEN_DEFAULT_MATRIX_FLAGS,
+         unsigned int _SuggestedFlags = EIGEN_DEFAULT_MATRIX_FLAGS,
          int _MaxRows = _Rows, int _MaxCols = _Cols>
 class Matrix;