Add simple documentation in comments, refactor.

Change all `unsigned int` and `unsigned long` types to `size_t`.
Fix names alignment in headers.

Add documentation and simple description:
Painter - painter.h
Main - tetris.c
Unicode - unicode.h
IDList - idlist.h
Engine - engine.c

Minor changes:
tetris.c - fix indentation and code blocks separation with newlines,
remove unused includes.
idlist.h - fix structure field name alignment.
field.h, engine.c - define aliases for ghost and active shapes indexes
in the field.
engine.c - rename menuTick to snake case, fix curly braces style of
functions.
Makefile - switch SFML deprecated warnings off.

1 files changed, 19 insertions, 10 deletions

diff --git a/include/idlist.h b/include/idlist.h
index 3318be4..c006a32 100644
--- a/include/idlist.h
+++ b/include/idlist.h
@@ -1,13 +1,22 @@
+/*
+ * idlist.h
+ *
+ * IDList - List datatype implementation. Element can be taken by id only.
+ *
+ * IDList is used by the Painter module and loadable texts.
+ *
+ * */
+
 struct idlist {
-    unsigned long id;
-    void        *obj;
-    struct idlist *next;
-    struct idlist *prev;
+    size_t          id;
+    void           *obj;
+    struct idlist  *next;
+    struct idlist  *prev;
 };
 
-struct idlist *list_new();
-struct idlist *list_append(struct idlist *list);
-struct idlist *list_get(const struct idlist *list, unsigned long id);
-void           list_rm_node(struct idlist *node);
-void           list_foreach(struct idlist *list, void (*job)(void *));
-void           list_destroy(struct idlist *list);
+struct idlist  *list_new();
+struct idlist  *list_append(struct idlist *list);
+struct idlist  *list_get(const struct idlist *list, size_t id);
+void            list_rm_node(struct idlist *node);
+void            list_foreach(struct idlist *list, void (*job)(void *));
+void            list_destroy(struct idlist *list);