Coordinate size limitation removed.

per-file comments:
  mysql-test/r/gis-precise.result
        test result updated.
  sql/gcalc_slicescan.cc
        Check coordinate extent to pick better precidion in the ::set_double()
  sql/gcalc_slicescan.h
        free_list() can lead to valgrind warnig. Fixed
  sql/gcalc_tools.cc
        free_list() call changed.