puzzles: refactor and resync with upstream

This brings puzzles up-to-date with upstream revision
2d333750272c3967cfd5cd3677572cddeaad5932, though certain changes made
by me, including cursor-only Untangle and some compilation fixes
remain. Upstream code has been moved to its separate subdirectory and
future syncs can be done by simply copying over the new sources.

Change-Id: Ia6506ca5f78c3627165ea6791d38db414ace0804

apps/plugins/puzzles/SOURCES

@@ -1,26 +1,26 @@
 rockbox.c
 rbwrappers.c
-
-combi.c
-divvy.c
-drawing.c
-dsf.c
-findloop.c
-grid.c
-latin.c
-laydomino.c
-loopgen.c
-malloc.c
-maxflow.c
-midend.c
-misc.c
-penrose.c
-printing.c
-random.c
-tdq.c
-tree234.c
-version.c
+rbmalloc.c
+src/combi.c
+src/divvy.c
+src/drawing.c
+src/dsf.c
+src/findloop.c
+src/grid.c
+src/latin.c
+src/laydomino.c
+src/loopgen.c
+/*src/malloc.c*/ /* we have our own */
+src/maxflow.c
+src/midend.c
+src/misc.c
+src/penrose.c
+src/printing.c
+src/random.c
+src/tdq.c
+src/tree234.c
+src/version.c
 
 #ifdef COMBINED
-list.c
+src/list.c
 #endif