Fixes #12 can't remove operators
Fixes #9 Configurable operators
fixes #11 No groups + remove main delete button instead of CSS hide
Fixes #10 Readonly mode
Fixes #14 add 'getSQL' method (documentation incoming)
error in getSQL on invalid rules
Fixes #15 wrong SQL equal operator
next version is 1.2.0
Fixes #16 can't remove conditions (rework #12 also)
When calling setRules with either empty data or no rules, some things may break.