Pulling LocalGemm and friends out of the internal namespace and merging HPDInverse with Inverse, HPDDeterminant with Determinant, SolveAfterCholesky with Cholesky, and SolveAfterLU with LU

--HG--
rename : include/elemental/lapack-like/SolveAfterCholesky.hpp => include/elemental/lapack-like/Cholesky/SolveAfter.hpp
rename : include/elemental/lapack-like/HPDDeterminant.hpp => include/elemental/lapack-like/Determinant/Cholesky.hpp
rename : include/elemental/lapack-like/CholeskySolve.hpp => include/elemental/lapack-like/HPDSolve.hpp
rename : include/elemental/lapack-like/HPDInverse/LVar2.hpp => include/elemental/lapack-like/Inverse/CholeskyLVar2.hpp
rename : include/elemental/lapack-like/HPDInverse/UVar2.hpp => include/elemental/lapack-like/Inverse/CholeskyUVar2.hpp
rename : include/elemental/lapack-like/SolveAfterLU.hpp => include/elemental/lapack-like/LU/SolveAfter.hpp