Bug#33812: mysql client incorrectly parsing DELIMITER
Remove unnecessary and incorrect code that tried
to pull delimiter commands out of the middle of
statements.
- Client side readline functions unconditionally search for Unix '\n' line
endings. In this case, the delimiter statement was set to '//\r' instead
of the intended '//'. When removing the '\n' check for and remove
preceeding '\r' character as well.
- Added testcases to test delimiters in 5.0
- In 5.0 it's allowed to have a up to 16 byte string as delimiter, everything after the delimiter token will be treated as the delimiter. It's even allowed to set delimiter to 'delimiter', ':;' or'MySQL'
