Problem: Unescaping of '\' characters didn't work when processing N'xxx'.
Fix: using get_text() instead of get_token() when scanning nationa strings.


mysql-test/r/ctype_utf8.result:
  Adding test case
mysql-test/t/ctype_utf8.test:
  Adding test case
sql/sql_lex.cc:
  Fixing to process national strings using get_tex(),
  i.e. the same way with usual strings, to make
  unescaping work.