x11/fireflies: Update to 2.08

Turned out there is a somewhat well-hidden new release available from
GitHub, it wasn't even mentioned on the new project homepage. This
version fixes build issues, it builds without local patches. There's
also at least some activity on the repository, so no need to deprecate
this port right now.

A fixed libgfx is now integrated in the source tree, so use this instead
of the external dependency.

Take maintainership.