Temporary Tutorial Fix

Currently, the last exercise that adds rules to parse "physicists born in Ulm" doesn't work, because the command

java -cp classes:lib/* edu.stanford.nlp.sempre.Main -executor SparqlExecutor -endpointUrl http://localhost:3093/sparql -interactive

is missing many flags that running ./sempre automatically sets. Until all the missing flags are identified/added, this temporary replacement instructs the user to call sempre using ./sempre instead (with an empty_grammar file to override the default emnlp grammar) so that the rules given in the Tutorial work properly.