PHP requires integer typehints to be written "int" and does not
allow "integer" as an alias. This changes type error messages to
match the actual type name and avoids confusing messages like
"must be of the type integer, integer given".
Added 2nd, optional, param to assert. When passed in it will be added
to the printed warnings and passed as a 4th param to a callback. PR 150
by Lonny Kapelushnik
