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

doc/examples/Tutorial_PartialLU_solve.cpp

@@ -12,6 +12,6 @@ int main(int, char *[])
    b << 3, 3, 4;
    cout << "Here is the matrix A:" << endl << A << endl;
    cout << "Here is the vector b:" << endl << b << endl;
-   Vector3f x = A.partialLu().solve(b);
+   Vector3f x = A.lu().solve(b);
    cout << "The solution is:" << endl << x << endl;
 }