Check UCS2 trailing spaces.


mysql-test/r/ctype_ucs.result:
  Move common trailing space checks into an include file.
  Check UCS2 trailing spaces.
  Fix UCS2 to handle trailing spaces in PAD way.
mysql-test/t/ctype_ucs.test:
  Move common trailing space checks into an include file.
  Check UCS2 trailing spaces.
  Fix UCS2 to handle trailing spaces in PAD way.
mysql-test/t/endspace.test:
  Move common trailing space checks into an include file.
  Check UCS2 trailing spaces.
  Fix UCS2 to handle trailing spaces in PAD way.
strings/ctype-ucs2.c:
  Move common trailing space checks into an include file.
  Check UCS2 trailing spaces.
  Fix UCS2 to handle trailing spaces in PAD way.