deleted 3 obsolete UDF functions (as superseded by GenericXXX UDFs).
covered functions "pmod" (class UDFPosMod), "test_max" (test class UDAFTestMax).
Merge branch 'fb-HIVE-4779-trunk-gd' of https://github.com/griddynamics/hive into fb-HIVE-4779-trunk-gd