[NEW] Added a function to compute a rotation matrix from a given surface normal



git-svn-id: svn://svn.code.sf.net/p/elmerfem/code/trunk@6868 04224531-1f84-46d8-96ce-875b9e37dce3
[NEW] Added functionality for rotated free surfaces in arbitrary direction.



git-svn-id: svn://svn.code.sf.net/p/elmerfem/code/trunk@6869 04224531-1f84-46d8-96ce-875b9e37dce3