minor improvements (fixes) to did-you-mean suggestions
sets: fix a bug in model building, another in handling set of sets
lfsc_checker: fix some warnings reported by _both_ gcc and clang
Merge pull request #26 from kbansal/sets

Sets
minor fix for string equality engine assertion.
Fixing documentation for glpk configuration.
More documentation fixes. Apologies for multiple commits.
Fix compiler warning (missing virtual dtor)
Disallow non-7-bit ASCII in SMT-LIB input.