Remove wrong redefine of vio_reset() (to compile libmysqld on windows)


include/violite.h:
  Remove wrong redefine of vio_reset()
support-files/my-huge.cnf.sh:
  Add read_rnd_buffer_size
support-files/my-large.cnf.sh:
  Add read_rnd_buffer_size
support-files/my-medium.cnf.sh:
  Add read_rnd_buffer_size
support-files/my-small.cnf.sh:
  Add read_rnd_buffer_size