Slight rework of random number generator.

- break dependence on OSystem; source for seed could actually be anything (doesn't have to come from OSystem)

src/emucore/OSystem.cxx

@@ -95,7 +95,6 @@ OSystem::OSystem()
 
   mySettings = MediaFactory::createSettings(*this);
   myAudioSettings = AudioSettings(mySettings.get());
-  myRandom = make_unique<Random>(*this);
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -158,8 +157,8 @@ bool OSystem::create()
   // a real serial port on the system
   mySerialPort = MediaFactory::createSerialPort();
 
-  // Re-initialize random seed
-  myRandom->initSeed();
+  // Create random number generator
+  myRandom = make_unique<Random>(getTicks());
 
   // Create PNG handler
   myPNGLib = make_unique<PNGLibrary>(*this);

src/emucore/Random.hxx

@@ -19,7 +19,6 @@
 #define RANDOM_HXX
 
 #include "bspf.hxx"
-#include "OSystem.hxx"
 #include "Serializable.hxx"
 
 /**
@@ -35,15 +34,15 @@ class Random : public Serializable
     /**
       Create a new random number generator
     */
-    Random(const OSystem& osystem) : myOSystem(osystem) { initSeed(); }
+    Random(uInt32 seed) { initSeed(seed); }
 
     /**
       Re-initialize the random number generator with a new seed,
       to generate a different set of random numbers.
     */
-    void initSeed()
+    void initSeed(uInt32 seed)
     {
-      myValue = uInt32(myOSystem.getTicks());
+      myValue = seed;
     }
 
     /**
@@ -110,9 +109,6 @@ class Random : public Serializable
     string name() const override { return "Random"; }
 
   private:
-    // Set the OSystem we're using
-    const OSystem& myOSystem;
-
     // Indicates the next random number
     // We make this mutable, since it's not immediately obvious that
     // calling next() should change internal state (ie, the *logical*

src/emucore/System.cxx

@@ -39,7 +39,7 @@ System::System(const OSystem& osystem, M6502& m6502, M6532& m6532,
     mySystemInAutodetect(false)
 {
   // Re-initialize random generator
-  randGenerator().initSeed();
+  randGenerator().initSeed(myOSystem.getTicks());
 
   // Initialize page access table
   PageAccess access(&myNullDevice, System::PA_READ);

src/emucore/System.hxx

@@ -27,6 +27,7 @@ class NullDevice;
 #include "bspf.hxx"
 #include "Device.hxx"
 #include "NullDev.hxx"
+#include "OSystem.hxx"
 #include "Random.hxx"
 #include "Serializable.hxx"