Adds option -logPreds for filtering log output.

[zafer-esen]

-logPreds:<preds> Log only predicates containing the specified substrings, separated by commas
                     e.g., -logPreds=p1,p2 logs any predicate with 'p1' or 'p2' in its name

The current implementation in this PR checks for substrings, mainly because predicate names change during pre-processing. This also gives flexibility when specifying predicate names, for instance one can specify a substring like main, and all predicates containing main would be logged.

Also,

• slightly rephrases help text for log related options,
• shows a more helpful text for incorrect options.