Removed and suppressed compiler warnings


mysql-test/suite/parts/t/rpl_partition.test:
  Mark as big test (as test takes > 5 minutes)
mysql-test/suite/rpl/t/rpl_row_trig003.test:
  Fixed random failure
sql/item_create.cc:
  Renamed create -> create_builder() to avoid compiler warnings about function hidden by others
sql/net_serv.cc:
  Removed compiler warning
support-files/compiler_warnings.supp:
  Supress some warnings
  Remove suppresstion from set_var.cc, as this has already been fixed
  Added missing \ before .c
  Added suppression of warnings that are due to gcc bug (.*discards qualifiers from pointer target type.*)