add/fix callbacks, allow multiple select, allow empty select (for plugin integration), add operators options (preceed excludedOperators)
add/fix callbacks,
allow multiple select,
allow empty select (for plugin integration),
add operators options (preceed excludedOperators)

javaronok/jQuery-QueryBuilder,lamguy/jQuery-QueryBuilder,elucidat/jQuery-QueryBuilder,pombredanne/jQuery-QueryBuilder,fashionsun/jQuery-QueryBuilder,mistic100/jQuery-QueryBuilder,fashionsun/jQuery-QueryBuilder,mistic100/jQuery-QueryBuilder,motoha/jQuery-QueryBuilder,javaronok/jQuery-QueryBuilder,rjstretch/jQuery-QueryBuilder,rjstretch/jQuery-QueryBuilder,lamguy/jQuery-QueryBuilder,kenwilcox/jQuery-QueryBuilder,kenwilcox/jQuery-QueryBuilder,chrisclarke1977/jQuery-QueryBuilder,jasondavis/jQuery-QueryBuilder,chrisclarke1977/jQuery-QueryBuilder,0xCCD/jQuery-QueryBuilder,motoha/jQuery-QueryBuilder,pombredanne/jQuery-QueryBuilder,jasondavis/jQuery-QueryBuilder