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, 1 insertions, 1 deletions

diff --git a/src/idlist.c b/src/idlist.c
index b9d551a..14db85f 100644
--- a/src/idlist.c
+++ b/src/idlist.c
@@ -21,7 +21,7 @@ struct idlist *list_append(struct idlist *list)
     return last->next;
 }
 
-struct idlist *list_get(const struct idlist *list, unsigned long id)
+struct idlist *list_get(const struct idlist *list, size_t id)
 {
     const struct idlist *sought = list;
     if (sought) {