Fix BV inequality solver caching.
BV inequality graph TNode fix.
Merge pull request #65 from mdeters/bv-ineq-cachefix

Fix BV inequality solver caching, and TNode fix.
Possible fix for bug594
More preparation for filtering relevant terms in TermDb.
Remove two obsolete versions of MBQI.
Merge pull request #69 from mdeters/bug594

Fix memory leak in CDHashMap<> with Node keys (resolves bug 594).
New, uniform checkTime statistic for all theories (as discussed in meeting).