release: bump the version to 2.4.1 (#703)

Two bug fixes since 2.4.0, both crashes on plain QF_BV and neither
reachable from the API in a new way: #699 guards the multiplication
column bounds against a shrunken column, and #702 stops the ground-path
square root's Newton seed overflowing at UINT64_MAX.

Nothing under include/ changed, so this is a patch bump. The soname
stays libstp.so.2.4 and STPConfigVersion keeps matching
find_package(STP 2.4) -- packagers pick this up without rebuilding
what links STP.

Both files that carry the version by hand, since the release workflow
refuses to build a tag that disagrees with either. The examples in
releasing.rst move with them, as they did for 2.4.0: the "where the
version lives" entries name what master now carries, and the tag
commands name the release after this one.

release: bump the version to 2.4.0 (#701)

232 commits since 2.3.4, and the public API has grown -- c_interface.h
and cpp_interface.h both gained symbols, though none were removed. That
is a minor bump rather than a patch one: the soname becomes libstp.so.2.4
and STPConfigVersion stops matching find_package(STP 2.3), so packagers
have to rebuild what links STP.

Both files that carry the version by hand, since the release workflow
refuses to build a tag that disagrees with either. The examples in
releasing.rst move with them, and the note about the v2.3.4 release
loses its "currently shows as latest", which stops being true as soon
as this ships.

If using Cadical, default to Cadical

use simple CNF encoding when simplifications are disabled

initial smtcomp 2020 mergesat.

Bumping version

Tagging 2.3.2

Related to #307

Adding SUSE build files

Fixing cryptominisat libraries location

Bumping version and releasing after KLEE build fix