Pressing F12 in the debugger saves snapshots (implements #161).

Changes.txt

@@ -69,6 +69,8 @@
       clearly indicate if an item can be modified.
     - Debugger '.lst' and '.sym' files are now searched based on the name
       of the ROM file, and not on the internal properties name.
+    - Snapshots can now be saved by pressing F12 key (the various other
+      ways to save snapshots still exist).
 
   * Mouse grabbing is now enabled in windowed mode only when the ROM is
     using a virtual analog controller (paddles, trakball, etc).

src/debugger/gui/DebuggerDialog.cxx

@@ -83,6 +83,10 @@ void DebuggerDialog::handleKeyDown(StellaKey key, StellaMod mod)
     // Swallow backtick, so we don't see it when exiting the debugger
     instance().eventHandler().enableTextEvents(false);
   }
+  else if(key == KBDK_F12)
+  {
+    instance().debugger().parser().run("savesnap");
+  }
   else if(instance().eventHandler().kbdControl(mod))
   {
     switch(key)