Fixed proper use of the gc to detect pike type leaks. Some other minor

fiddling with the leak reports.

Rev: src/gc.c:1.302
Rev: src/global.h:1.111
Rev: src/module.c:1.50
Rev: src/pike_types.c:1.318
Rev: src/pike_types.h:1.111
Rev: src/program.c:1.656
Rev: src/svalue.c:1.238