Did major cleanup, as Amanieu reccomended

Applied Semi Mark Fix (Issue 84)
Applied MediStation shove control (Issue 85)
Fixed g_modhumanstamina, now affects jums too (Issue 86)
Applied high turret angles (Issue 87)
Changed !demo to the PROPER adminchat flag (?)

src/game/g_admin.c

@@ -104,7 +104,7 @@ g_admin_cmd_t g_admin_cmds[ ] =
       "[^3name|slot#^7] [^3#^7]"
     },
 
-    {"demo", G_admin_demo, "~",
+    {"demo", G_admin_demo, "?",
       "turn admin chat off for the caller so it does not appear in demos. "
       "this is a toggle use !demo again to turn warnings back on",
       ""