add: implemented #122.

fix: bots try to defuse already beeing defused bomb (fixes #116).
fix: line ending in source code.
fix:  do not retreat with sniper weapon, if currently shooting and have ammo.
crlib: added deque class.

inc/engine.h

@@ -355,6 +355,11 @@ public:
       return !m_breakables.empty ();
    }
 
+   // find variable value by variable name
+   StringRef findCvar (StringRef name) {
+      return engfuncs.pfnCVarGetString (name.chars ());
+   }
+
    // helper to sending the client message
    void sendClientMessage (bool console, edict_t *ent, const char *message);