Miscellaneous fixes from James Harvey's PalmOS porting work:

- fixed numerous memory leaks (not Palm-specific)
 - corrected a couple of 32-bit-int assumptions (vital for Palm but
   generally a good thing anyway)
 - lifted a few function pointer types into explicit typedefs
   (neutral for me but convenient for the source-munging Perl
   scripts he uses to deal with Palm code segment rules)
 - lifted a few function-level static arrays into global static
   arrays (neutral for me but apparently works round a Palm tools
   bug)
 - a couple more presets in Rectangles (so that Palm, or any other
   slow platform which can't handle the larger sizes easily, can
   still have some variety available)
 - in Solo, arranged a means of sharing scratch space between calls
   to nsolve to prevent a lot of redundant malloc/frees (gives a 10%
   speed increase even on existing platforms)

[originally from svn r5897]

malloc.c

@@ -10,7 +10,7 @@
  * smalloc should guarantee to return a useful pointer - Halibut
  * can do nothing except die when it's out of memory anyway.
  */
-void *smalloc(int size) {
+void *smalloc(size_t size) {
     void *p;
     p = malloc(size);
     if (!p)
@@ -30,7 +30,7 @@ void sfree(void *p) {
 /*
  * srealloc should guaranteeably be able to realloc NULL
  */
-void *srealloc(void *p, int size) {
+void *srealloc(void *p, size_t size) {
     void *q;
     if (p) {
 	q = realloc(p, size);