big huge changes, so i dont remember everything.

* renaming, e.g. LU ---> FullPivLU
* split tests framework: more robust, e.g. dont generate empty tests if a number is skipped
* make all remaining tests use that splitting, as needed.
* Fix 4x4 inversion (see stable branch)
* Transform::inverse() and geo_transform test : adapt to new inverse() API, it was also trying to instantiate inverse() for 3x4 matrices.
* CMakeLists: more robust regexp to parse the version number
* misc fixes in unit tests

Eigen/src/Sparse/SparseLU.h

@@ -39,7 +39,7 @@ enum {
   *
   * \param MatrixType the type of the matrix of which we are computing the LU factorization
   *
-  * \sa class LU, class SparseLLT
+  * \sa class FullPivLU, class SparseLLT
   */
 template<typename MatrixType, int Backend = DefaultBackend>
 class SparseLU