* Much better, consistent error msgs when mixing different scalar types:

- in matrix-matrix product, static assert on the two scalar types to be the same.
- Similarly in CwiseBinaryOp. POTENTIALLY CONTROVERSIAL: we don't allow anymore binary
  ops to take two different scalar types. The functors that we defined take two args
  of the same type anyway; also we still allow the return type to be different.
  Again the reason is that different scalar types are incompatible with vectorization.
  Better have the user realize explicitly what mixing different numeric types costs him
  in terms of performance.
  See comment in CwiseBinaryOp constructor.
- This allowed to fix a little mistake in test/regression.cpp, mixing float and double
- Remove redundant semicolon (;) after static asserts

Eigen/src/Core/util/StaticAssert.h

@@ -60,23 +60,24 @@
         you_mixed_matrices_of_different_sizes,
         this_method_is_only_for_vectors_of_a_specific_size,
         this_method_is_only_for_matrices_of_a_specific_size,
-        you_did_a_programming_error,
+        you_made_a_programming_mistake,
         you_called_a_fixed_size_method_on_a_dynamic_size_matrix_or_vector,
         unaligned_load_and_store_operations_unimplemented_on_AltiVec,
-        scalar_type_must_be_floating_point,
-        default_writting_to_selfadjoint_not_supported,
-        writting_to_triangular_part_with_unit_diag_is_not_supported,
+        numeric_type_must_be_floating_point,
+        default_writing_to_selfadjoint_not_supported,
+        writing_to_triangular_part_with_unit_diagonal_is_not_supported,
         this_method_is_only_for_fixed_size,
         invalid_matrix_product,
         invalid_vector_vector_product__if_you_wanted_a_dot_or_coeff_wise_product_you_must_use_the_explicit_functions,
-        invalid_matrix_product__if_you_wanted_a_coeff_wise_product_you_must_use_the_explicit_function
+        invalid_matrix_product__if_you_wanted_a_coeff_wise_product_you_must_use_the_explicit_function,
+	you_mixed_different_numeric_types__you_need_to_use_the_cast_method_of_MatrixBase_to_cast_numeric_types_explicitly
       };
     };
 
     #define EIGEN_STATIC_ASSERT(CONDITION,MSG) \
       if (Eigen::ei_static_assert<CONDITION ? true : false>::MSG) {}
 
-  #endif // CXX0X
+  #endif // not CXX0X
 
 #else // EIGEN_NO_STATIC_ASSERT
 
@@ -121,7 +122,7 @@
     || int(TYPE1::ColsAtCompileTime)==Eigen::Dynamic \
     || int(TYPE0::ColsAtCompileTime)==int(TYPE1::ColsAtCompileTime)))
 
-// static assertion failing if the two matrix expression types are not compatible (same fixed-size or dynamic size)
+// static assertion failing if it is guaranteed at compile-time that the two matrix expression types have different sizes
 #define EIGEN_STATIC_ASSERT_SAME_MATRIX_SIZE(TYPE0,TYPE1) \
   EIGEN_STATIC_ASSERT( \
      EIGEN_PREDICATE_SAME_MATRIX_SIZE(TYPE0,TYPE1),\