new features in 465r2
---------------------

fixedto incremental usage of blocked clauses

new features in 465 since 236
-----------------------------
blocked clause elimination
glucose glueing
preprocessing run-to-completion mode
stand alone preprocessing
on-the-fly subsumption
allow one proper inverse arc but disabled
application interface similar to PicoSAT without assumptions yet
added backward subsumption and strengthening for learned clauses
removed hash table for binary clauses
