This is a exception to be thrown when the error occures because
of bad user data. We don't want to print a full stack trace in
these cases but just tell the user what went wrong.
The new functions always creates normal and partitioned functions.
Also adds specialised connection and cursor classes for adding
frequently used helper functions.
Adds infrastructure for calling the legacy PHP scripts. As the
CONST_* values cannot be set from the python script, hand the values
in via secret environment variables instead. These are all
temporary hacks for the transition phase to python code.
