instn cst
fix a bug in genReport
1. applocal should alway contain vvalias pairs. 2. improve precision in cst.
instn skip completed, need testing
1. change the weakupdate cache a bit to make it fine-grained 2. instnSkip seems not work well, need to check out why 3. change the constraint instantiation factory by including a sub-factory for each (call site, callee) pair
Merge branch 'master' of github.com:xwangsd/Scuba