After this afternoon's accidental update, fix the port and complete
the update.
- Spectral expects some unreleased and unpackaged dependencies, which
is why the DISTFILES are a mess: it's gitlab, except this one
dependency on github, and this other one.
- libQuotient is net-im/libQuaternion, except that spectral needs a
newer-than-the-latest-unreleased version.
- there is a rather arbitrary and hackish patch to avoid a compile
error -- during template expansion of visit() I sometimes got
a compiler crash, more often an error about returning a value in
a void function. Since the whole package is glued together with
unreleased submodules, I spent some time trying to fix it, and
then decided that this is non-essential functionality. Two
events trigger the compile error, so I commented them out.
PORTREVISION bumped because there's a tiny chance that something
might have built out of the mess that there was earlier.