Initial port to Linux (using Allegro).

64-bit fixes.
Some changes to aid portability.
A few other tweaks.

src/allegro-joystick.c

@@ -0,0 +1,30 @@
+#include "allegro-main.h"
+#include "plat-joystick.h"
+
+joystick_t joystick_state[2];
+int joysticks_present;
+
+void joystick_init()
+{
+        install_joystick(JOY_TYPE_AUTODETECT);
+        joysticks_present = MIN(num_joysticks, 2);
+}
+void joystick_close()
+{
+}
+void joystick_poll()
+{
+        int c;
+        
+        poll_joystick();
+
+        for (c = 0; c < MIN(num_joysticks, 2); c++)
+        {                
+                joystick_state[c].x = joy[c].stick[0].axis[0].pos * 256;
+                joystick_state[c].y = joy[c].stick[0].axis[1].pos * 256;
+                joystick_state[c].b[0] = joy[c].button[0].b;
+                joystick_state[c].b[1] = joy[c].button[1].b;
+                joystick_state[c].b[2] = joy[c].button[2].b;
+                joystick_state[c].b[3] = joy[c].button[3].b;
+        }
+}