Empty strings (and names with trailing spaces) should not be allowed.


mysql-test/r/sp-error.result:
  New testcase for BUG#15658
mysql-test/t/sp-error.test:
  New testcase for BUG#15658
sql/share/errmsg.txt:
  New error message for bad stored routine names.
sql/sp_head.cc:
  Added function for checking SP names. (Mustn't be empty or contain trailing spaces.)
sql/sp_head.h:
  Added function for checking SP names.
sql/sql_yacc.yy:
  Check db and name for stored routines.