dev-libs/gecode: new version 4.4.0.

dev-libs/gecode: new version 4.4.0.

This version bump fixes at least two open bugs. The first simply asked
for a version bump, and the second reported a failure when /bin/sh is
dash (now fixed).

Along with the new version, some ebuild cleanup was done. The ebuild
is now EAPI=6, and the "gmp" USE flag was added to control building
with float constraints. Three superfluous runtime dependencies
(transitive through Qt) were removed, and two new build dependencies
needed to generate the documentation were added.

The src_test() phase has been re-enabled with an LD_LIBRARY hack to
make sure that the test suite is run against the just-build libraries.

Gentoo-Bug: 377091
Gentoo-bug: 527526
Gentoo-Bug: 567208

Package-Manager: portage-2.2.28