proisstrict must be assumed FALSE when dumping from a 7.0 database,

proisstrict must be assumed FALSE when dumping from a 7.0 database,
not TRUE.  Otherwise we break pl call handler functions.  fmgr_oldstyle
will take care of making sure the semantics are the same for C functions.
Clean up some slightly grotty coding in 7.0 pg_class reading, also.