Break inclusion cycle: prototypes.h and commands.h included each

other.  Ensure headers in include/ can be included in any order
(except for econfig-spec.h, which is special).  New header types.h to
help avoid inclusion cycles.  Sort include directives.  Remove some
superflous includes.

src/lib/global/file.c

@@ -34,26 +34,22 @@
 #include <config.h>
 
 #include <stddef.h>
-#include "misc.h"
-#include "xy.h"
+#include "commodity.h"
+#include "file.h"
+#include "land.h"
 #include "loan.h"
+#include "lost.h"
+#include "nat.h"
+#include "news.h"
 #include "nsc.h"
 #include "nuke.h"
 #include "plane.h"
-#include "ship.h"
-#include "land.h"
+#include "power.h"
+#include "product.h"
 #include "sect.h"
+#include "ship.h"
 #include "trade.h"
 #include "treaty.h"
-#include "file.h"
-#include "power.h"
-#include "news.h"
-#include "nat.h"
-#include "lost.h"
-#include "product.h"
-
-#include "commodity.h"
-#include "nsc.h"
 
 /* Number of elements in ARRAY.  */
 #define SZ(array) (sizeof(array) / sizeof((array)[0]))

src/lib/global/init.c

@@ -34,12 +34,13 @@
 
 #include <config.h>
 
+#include "land.h"
 #include "misc.h"
-#include "ship.h"
+#include "optlist.h"
 #include "plane.h"
 #include "product.h"
-#include "optlist.h"
 #include "prototypes.h"
+#include "ship.h"
 
 static void init_mchr(void);
 static void init_pchr(void);

src/lib/global/item.c

@@ -33,7 +33,6 @@
 
 #include <config.h>
 
-#include "misc.h"
 #include "item.h"
 
 /*

src/lib/global/land.c

@@ -35,7 +35,6 @@
 
 #include <config.h>
 
-#include "misc.h"
 #include "land.h"
 
 /*

src/lib/global/news.c

@@ -41,9 +41,7 @@
 
 #include <config.h>
 
-#include "misc.h"
 #include "news.h"
-#include "nsc.h"
 
 static char no_news[] = "does nothing in particular to %s";
 

src/lib/global/nsc.c

@@ -39,12 +39,10 @@
 #include <config.h>
 
 #include <stddef.h>
-#include "misc.h"
-#include "xy.h"
-#include "nsc.h"
 #include "empobj.h"
-#include "product.h"
 #include "file.h"
+#include "nsc.h"
+#include "product.h"
 
 #define fldoff(str, fld) offsetof(struct str, fld)
 

src/lib/global/nuke.c

@@ -33,7 +33,6 @@
 
 #include <config.h>
 
-#include "misc.h"
 #include "nuke.h"
 
 /*

src/lib/global/plane.c

@@ -37,7 +37,6 @@
 
 #include <config.h>
 
-#include "misc.h"
 #include "plane.h"
 
 /*

src/lib/global/product.c

@@ -33,7 +33,6 @@
 
 #include <config.h>
 
-#include "misc.h"
 #include "product.h"
 
 /*

src/lib/global/sect.c

@@ -37,7 +37,6 @@
 
 #include <config.h>
 
-#include "misc.h"
 #include "sect.h"
 
 /*

src/lib/global/ship.c

@@ -37,7 +37,6 @@
 
 #include <config.h>
 
-#include "misc.h"
 #include "ship.h"
 
 /*

src/lib/global/symbol.c

@@ -34,11 +34,16 @@
 #include <config.h>
 
 #include "land.h"
+#include "misc.h"
 #include "mission.h"
+#include "nat.h"
 #include "news.h"
+#include "nsc.h"
 #include "nuke.h"
 #include "plague.h"
 #include "plane.h"
+#include "retreat.h"
+#include "sect.h"
 #include "ship.h"
 #include "treaty.h"