Imported the check for updates code from StepMania AMX.

---
TODO: Move the code from NSMAN to a new class
TODO: HOOKS->GetURL for Linux
TODO: Do not run the check every time the game is launched, use:
PREFSMAN->m_iUpdateCheckIntervalSeconds - Seconds to wait before running the next check
PREFSMAN->m_iUpdateCheckLastCheckedSecond - Timestamp of the last check

src/PrefsManager.cpp

@@ -143,6 +143,10 @@ bool g_bAutoRestart = false;
 # define TRUE_IF_DEBUG false
 #endif
 
+#if !defined(WITHOUT_NETWORKING) && defined(HAVE_VERSION_INFO)
+extern unsigned long version_num;
+#endif
+
 void ValidateDisplayAspectRatio( float &val )
 {
 	if( val < 0 )
@@ -289,6 +293,19 @@ PrefsManager::PrefsManager() :
 #if !defined(WITHOUT_NETWORKING)
 	,
 	m_bEnableScoreboard		( "EnableScoreboard",	true )
+
+	#if defined(HAVE_VERSION_INFO)
+		,
+		m_bUpdateCheckEnable			( "UpdateCheckEnable",				true )
+		// TODO - Aldo_MX: Use PREFSMAN->m_iUpdateCheckIntervalSeconds & PREFSMAN->m_iUpdateCheckLastCheckedSecond
+		//,
+		//m_iUpdateCheckIntervalSeconds	( "UpdateCheckIntervalSeconds",		86400 ),	// 24 hours
+		//m_iUpdateCheckLastCheckedSecond	( "UpdateCheckLastCheckSecond",		0 )
+
+		// TODO - Aldo_MX: Write helpers in LuaManager.cpp to treat unsigned int/long like LUA Numbers
+		//,
+		//m_uUpdateCheckLastCheckedBuild	( "UpdateCheckLastCheckedBuild",	version_num )
+	#endif
 #endif
 
 {