in-house of blas/lapack)

without recompiling

fix recombine with embedded edges

Third phase of code refactoring: move callbacks where they belong
& drastically reduce namespace pollution.

There's no new functionality for now: PLEASE TEST THAT EVERYTHING
WORKS AS IT USED TO BEFORE.

workaround faulty fltk installs (e.g. in current Debian or Ubuntu)

There's no new functionality for now: PLEASE TEST THAT EVERYTHING
WORKS AS IT USED TO BEFORE.

multi-window & multi-coordinate system drawing.

There's no new functionality for now: PLEASE TEST THAT EVERYTHING
WORKS AS IT USED TO BEFORE.