Import of custom ebuilds I wrote for Mantid back in December 2013
Made some formatting changes as suggested by Sébastien Fabbro

Removed some unnecessary stuff from the ebuilds
Used the fortran-2 eclass
Using epatch instead of patch
Added a metadata.xml for minixml

Also fixed minor repoman niggles
Recalculated Manifest for minixml
Added metadata.xml to NeXus and generally tidied up

Now also using the java-pkg-opt-2 eclass
NeXus: handling of dependencies between Fortran module files doesn't play well with parallel make
NeXus: workaround for -fPIC error in Fortran build

see http://www.gentoo.org/proj/en/base/amd64/howtos/?part=1&chap=3
That didn't work, trying append-flags before econf instead of before emake
Duh! I have to use flag-o-matic to use append-flags