issue2551078 - Fix traceback caused when putting two id's into a Link html field. A ValueError is raised. Handle exception and return invalid value. hyperdb.py now reports 'you may only enter ID values for property ...' to the user.

#!/usr/bin/env python
from __future__ import print_function
import zlib, base64, sys
print(base64.encodestring(zlib.compress(sys.stdin.read())))