axiomlib: added AxiomExprSet::setName()

Signed-off-by: Victor Shcherbinin <victorshch@gmail.com>
axiomlib: added serialization of multimarkups and operator < to AxiomExprSetPlus

Signed-off-by: Victor Shcherbinin <victorshch@gmail.com>
axiomlib: fixed const references in some methods of AxiomSetBase

Plain references were used in some methods where const references should've been.
It created a huge inconvinience for writing calling code.

Signed-off-by: Victor Shcherbinin <victorshch@gmail.com>
axiomlib: axiomsets are now sorted by objective function value at the end of fuzzymultidataext algorithm (not sure if they were sorted before)

Signed-off-by: Victor Shcherbinin <victorshch@gmail.com>
axiomlib: best axiomsets are now serialized to XML at the end of fuzzymultidataext

Also added a function for loading axiomsets from XML.

Signed-off-by: Victor Shcherbinin <victorshch@gmail.com>
axiomlib: fixed serialization export header for elem conditions

Signed-off-by: Victor Shcherbinin <victorshch@gmail.com>
axiomlib: test_execute_fuzzy (the utility for running axiomsets) now works

This utility now loads axiomsets form XML files.

Signed-off-by: Victor Shcherbinin <victorshch@gmail.com>
axiomlib: test_fmd_extended now saves resulting axiomsets to XML files

Signed-off-by: Victor Shcherbinin <victorshch@gmail.com>