Gracefully close the app on exit (#12)

* Gracefully close the app on exit

* Application tear down

instead of calling Environment.Exit(0); do a better tear down of the application

Ryujinx/OsHle/Svc/SvcSystem.cs

@@ -9,6 +9,8 @@ namespace Ryujinx.OsHle.Svc
 {
     partial class SvcHandler
     {
+        private void SvcExitProcess(ARegisters Registers) => Ns.Os.ExitProcess(Registers.ProcessId);
+
         private void SvcCloseHandle(ARegisters Registers)
         {
             int Handle = (int)Registers.X0;