Log message:
Drop superfluous PKG_DESTDIR_SUPPORT, "user-destdir" is default these days.
Mark packages that don't or might probably not have staged installation.

Log message:
Import gmm-4.0.0 as wip/gmm.

Gmm++ is a generic C++ template library for sparse, dense and skyline matrices.
It is built as a set of generic algorithms (mult, add, copy, sub-matrices,
dense and sparse solvers ...) for any interfaced vector type or matrix type.
It can be view as a glue library allowing cooperation between several vector
and matrix types. However, basic sparse, dense and skyline matrix/vector types
are built in Gmm++, hence it can be used as a standalone linear algebra library.
Interfacing a vector or matrix type means writing "traits" objects called
"linalg_traits", which describe their properties. The library offers \ 
predefined
dense, sparse and skyline matrix types.