Another attempt at better organizing the lapack-like include folder

--HG--
rename : include/elemental/lapack-like/SortEig.hpp => include/elemental/lapack-like/HermitianEig/Sort.hpp
rename : include/elemental/lapack-like/Halley.hpp => include/elemental/lapack-like/Polar/Halley.hpp
rename : include/elemental/lapack-like/QDWH.hpp => include/elemental/lapack-like/Polar/QDWH.hpp