More work on fixing gc integration with types. More refinements of the leak report. Rev: src/gc.c:1.304 Rev: src/gc.h:1.130 Rev: src/module.c:1.51 Rev: src/pike_types.c:1.319 Rev: src/pike_types.h:1.112 Rev: src/svalue.c:1.239 Rev: src/svalue.h:1.156