handle better cancellation for parallel, switch between cube mode and base level mode in smt.threads, expose parameters to control theory_bv and phase caching

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

src/smt/smt_context.cpp

@@ -3963,6 +3963,7 @@ namespace smt {
         }
     }
 
+
     bool context::resolve_conflict() {
         m_stats.m_num_conflicts++;
         m_num_conflicts ++;