rogue4, arogue5: improve portability.

Most changes merely prevent including header files that don't exist.

All games now build and run on MinGW, though bugs remain.

rogue4/mdport.c

@@ -29,6 +29,10 @@
     SUCH DAMAGE.
 */
 
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
 #if defined(_WIN32)
 #include <Windows.h>
 #include <Lmcons.h>
@@ -40,10 +44,15 @@
 #undef MOUSE_MOVED
 #elif defined(__DJGPP__)
 #include <process.h>
-#else
+#endif
+
+#ifdef HAVE_PWD_H
 #include <pwd.h>
-#include <sys/utsname.h>
+#endif
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
+#ifdef HAVE_UTMPX_H
 #include <utmpx.h>
 #endif
 
@@ -60,7 +69,7 @@ char *strdup(const char *s);
 #endif
 
 #include <curses.h>
-#if !defined(DJGPP)
+#ifdef HAVE_TERM_H
 #include <term.h>
 #endif
 
@@ -657,28 +666,6 @@ md_memused()
 #endif
 }
 
-char *
-md_gethostname()
-{
-    static char nodename[80];
-    char *n = NULL;
-#if !defined(_WIN32) && !defined(__DJGPP__)
-    struct utsname ourname;
-
-    if (uname(&ourname) == 0)
-        n = ourname.nodename;
-#endif
-    if ((n == NULL) || (*n == '\0'))
-        if ( (n = getenv("COMPUTERNAME")) == NULL)
-            if ( (n = getenv("HOSTNAME")) == NULL)
-                n = "localhost";
-
-    strncpy(nodename, n, 80);
-    nodename[79] = 0;
-
-    return(nodename);
-}
-
 int
 md_erasechar()
 {