Engine: Apply Serenity fixes

A few fixes to get this running on Serenity.
    -The call to `mremap` has been removed
    -First video mode is hardcoded as video options crash the game
    -RESOURCE_LIBDIR has been hardcoded to /usr/local/lib/
    -Remove Linux specific headers
    -Fix SDL2 include path in source files
    -Replace stricmp with strcmp for now

Author: Quaker762

src/linux/net_udp.c

@@ -496,7 +496,7 @@ int NET_Socket (char *net_interface, int port)
         return 0;
     }
 
-    if (!net_interface || !net_interface[0] || !stricmp(net_interface, "localhost"))
+    if (!net_interface || !net_interface[0] || !strcmp(net_interface, "localhost"))
         address.sin_addr.s_addr = INADDR_ANY;
     else
         NET_StringToSockaddr (net_interface, (struct sockaddr *)&address);

src/linux/q_shlinux.c

@@ -97,11 +97,13 @@ int Hunk_End (void)
     n = munmap(unmap_base, unmap_len) + membase;
   }
 #endif
-#if defined(__linux__)
-    n = mremap(membase, maxhunksize, curhunksize + sizeof(int), 0);
+// HACK: This code crashes Quake2 on launch in Serenity. 
+// It works just fine without it, but this should _definitely_ be implemented eventually.
+#if defined(__linux__) || defined(__serenity__)
+    //n = mremap(membase, maxhunksize, curhunksize + sizeof(int), 0);
 #endif
-    if (n != membase)
-        Sys_Error("Hunk_End:  Could not remap virtual block (%d)", errno);
+    //if (n != membase)
+        //Sys_Error("Hunk_End:  Could not remap virtual block (%d)", errno);
     *((int *)membase) = curhunksize + sizeof(int);
 
     return curhunksize;

src/linux/rw_sdl.c

@@ -20,7 +20,7 @@
 #include <string.h>
 #include <sys/mman.h>
 
-#include <SDL.h>
+#include <SDL2/SDL.h>
 
 #ifdef OPENGL
 #include <GL/gl.h>

src/linux/snd_sdl.c

@@ -2,7 +2,7 @@
     snd_sdl.c
 
     Sound code taken from SDLQuake and modified to work with Quake2
-    Robert Bäuml 2001-12-25
+    Robert B�uml 2001-12-25
 
     This program is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
@@ -25,7 +25,7 @@
     $Id: snd_sdl.c,v 1.2 2002/02/09 20:29:38 relnev Exp $
 */
 
-#include <SDL.h>
+#include <SDL2/SDL.h>
 
 #include "../client/client.h"
 #include "../client/snd_loc.h"