Feature: Allow calling execute- functions with superfluous parameters

[jurov]

If execute- function is called with parameters that aren't used the actual query (both named and positional) it fails. I ran into it when constructing nontrivial queries and it would simplify the program if they were more pemissive. The change seems to be trivial, but I'm not sure which option makes most sense:

a) keep as is - superfluous parameters cause error, missing parameters are implicitly bound to null
b) default permissive - any superfluous parameters are ignored, any missing parameters are bound to null
c) default strict - set of parameters must exactly match the query

I'd prefer c) with the option lax-parameters that would switch the behavior to b)