Combining Norm/HermitianNorm/SymmetricNorm folders and creating elem::lq and elem::qr namespaces in a manner similar to elem::svd.

--HG--
rename : include/elemental/lapack-like/ExplicitLQ.hpp => include/elemental/lapack-like/LQ/Explicit.hpp
rename : include/elemental/lapack-like/LQ/Panel.hpp => include/elemental/lapack-like/LQ/PanelHouseholder.hpp
rename : include/elemental/lapack-like/TwoNormLowerBound.hpp => include/elemental/lapack-like/Norm/TwoLowerBound.hpp
rename : include/elemental/lapack-like/TwoNormUpperBound.hpp => include/elemental/lapack-like/Norm/TwoUpperBound.hpp
rename : include/elemental/lapack-like/CholeskyQR.hpp => include/elemental/lapack-like/QR/Cholesky.hpp
rename : include/elemental/lapack-like/ExplicitQR.hpp => include/elemental/lapack-like/QR/Explicit.hpp
rename : include/elemental/lapack-like/QR/Panel.hpp => include/elemental/lapack-like/QR/PanelHouseholder.hpp