DEBUG_MALLOC now usable, only minor leaks in compiler left as far as I know

Rev: src/array.c:1.24
Rev: src/dmalloc.h:1.2
Rev: src/error.h:1.8
Rev: src/language.yacc:1.52
Rev: src/las.c:1.41
Rev: src/las.h:1.10
Rev: src/lex.c:1.37
Rev: src/main.c:1.29
Rev: src/modules/Gmp/mpz_glue.c:1.25
Rev: src/modules/Image/colortable.c:1.30
Rev: src/modules/Image/encodings/pnm.c:1.6
Rev: src/object.c:1.31
Rev: src/object.h:1.13
Rev: src/pike_memory.c:1.7
Rev: src/pike_types.c:1.29
Rev: src/stralloc.c:1.20
Rev: src/svalue.h:1.11
Rev: src/testsuite.in:1.64