replace jars from esper-4.9.0 to esper-5.0
Update code with esper-5.0 (and antlr4)
 * fix required jar versions
 * fix AST traversing with antlr4 internals
   * and new esper-5 node definitions
 * fix test cases about whitespaces
   * "toEPL" method on esper-5 does NOT produce whitespace for
     * operators: ("1 + 2" -> "1+2")
     * arguments of functions: ("foo(1, 2)" -> "foo(1,2)")
 * hotfix for MIN()/MAX()
   * for http://jira.codehaus.org/browse/ESPER-788
separate examples and fix code styles (deleted in false)
support Group By ROLLUP, Grouping Sets and CUBE, and add tests
fix to simplify statement model traverse