Merge the "CPC Mode 5" branch to trunk.

Note this alsoincludes the "oldies" branch.

This has the following consequences :
[C64]
 * Loading and saving of screen-only, and color-only C64 picture is removed
 * Loading and saving in FLI mode is now possible
 * FLI constraint checker : tries to convert your image to FLI format, and put all the areas where it couldn't find a solution in a separate layer for you to fixup
 * This is currently accessible only with a shortcut. Menu will come next.
[Amstrad CPC]
 * Loading and saving of pictures in "Mode 5" is now possible. This custom format allows overscan mode 1 with rasters on 2 inks and split rasters on a 3rd one.
 * Mode 5 constraint enforcer : will ensure you can only draw pictures that are valid in mode 5. Each ink is seen as a layer.
 * This is accessible from a new button in the FX menu.
[Generic]
 * Added patch as I saw it : platform that don't support reporting "free space" on disk will not display anything (instead of "0 bytesÃ" as before)
 * For other platforms, when the free space is 0, we now have a disk full message.

The merge was not straight forward. I hope I didn't break too much things.


git-svn-id: svn://pulkomandy.tk/GrafX2/trunk@1810 416bcca6-2ee7-4201-b75f-2eb2f807beb1

src/engine.c

@@ -1292,6 +1292,11 @@ void Main_handler(void)
                 Layer_activate((key_index-SPECIAL_LAYER1_TOGGLE)/2, RIGHT_SIDE);
                 action++;
                 break;
+              case SPECIAL_FORMAT_CHECKER:
+                C64_FLI_enforcer();
+                action++;
+                break;
+
               case SPECIAL_REPEAT_SCRIPT:
 #ifdef __ENABLE_LUA__
                 Repeat_script();