Fix:
 * crashes on memory allocation failure found with failmalloc
 * memory leaks found with valgrind
 * compiler warnings in opt mode which would lead to invalid memory reads
 * problem using wrong name in decimal module reported by pychecker

Update the valgrind suppressions file with new leaks that are small/one-time
leaks we don't care about (ie, they are too hard to fix).

TBR=barry
TESTED=./python -E -tt ./Lib/test/regrtest.py -uall (both debug and opt modes)
  in opt mode:
  valgrind -q --leak-check=yes --suppressions=Misc/valgrind-python.supp \
    ./python -E -tt ./Lib/test/regrtest.py -uall,-bsddb,-compiler \
                        -x test_logging test_ssl test_multiprocessing
  valgrind -q --leak-check=yes --suppressions=Misc/valgrind-python.supp \
    ./python -E -tt ./Lib/test/regrtest.py test_multiprocessing
  for i in `seq 1 4000` ; do
    LD_PRELOAD=~/local/lib/libfailmalloc.so FAILMALLOC_INTERVAL=$i \
        ./python -c pass
  done

At least some of these fixes should probably be backported to 2.5.
diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index bd4f494..bdd9bd7 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -132,8 +132,8 @@
 	PyThreadState *tstate;
 	PyObject *bimod, *sysmod;
 	char *p;
-	char *icodeset; /* On Windows, input codeset may theoretically 
-			   differ from output codeset. */
+	char *icodeset = NULL; /* On Windows, input codeset may theoretically 
+			          differ from output codeset. */
 	char *codeset = NULL;
 	char *errors = NULL;
 	int free_codeset = 0;