better type checking implemented (and a bug in the type checking fixed) Rev: src/builtin_functions.c:1.76 Rev: src/docode.c:1.33 Rev: src/las.c:1.55 Rev: src/operators.c:1.28 Rev: src/pike_types.c:1.34 Rev: src/program.c:1.65 Rev: src/stralloc.c:1.28 Rev: src/svalue.h:1.13