Fix for ite of >=64bit wide bitvectors with unconstrained condition.
fix for hiding prompt/header in shell, error-behavior options as in SMTLIB
Merge pull request #21 from pcc/ite-fix

Fix for ite of >=64bit wide bitvectors with unconstrained condition.
Reduced example from pcc's bug report.
Merge branch 'master' of https://github.com/CVC4/CVC4