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, 12 insertions, 2 deletions

diff --git a/include/unicode.h b/include/unicode.h
index 0a34ce3..4e5910a 100644
--- a/include/unicode.h
+++ b/include/unicode.h
@@ -1,2 +1,12 @@
-unsigned long  utf8_strlen(char *string);
-void           utf8to32_strcpy(wchar_t *dest, char *src);
+/*
+ * unicode.h
+ *
+ * Unicode - module with some helper unicode functions.
+ *
+ * SFML uses UTF32 encoding for texts and there is no need to use any full
+ * featured library just for a couple of encoding conversion functions.
+ *
+ * */
+
+size_t  utf8_strlen(char *string);
+void    utf8to32_strcpy(wchar_t *dest, char *src);