Default positions for new dialogs.

I've tested these as best I can, but my display scaling might have confounded my attempts. Please test before merging!

src/gui/gui.cpp

@@ -1244,6 +1244,26 @@ Pos=60,60\n\
 Size=300,300\n\
 Collapsed=0\n\
 \n\
+[Window][Multi-Ins Setup]\n\
+Pos=858,549\n\
+Size=193,129\n\
+Collapsed=0\n\
+\n\
+[Window][Spectrum]\n\
+Pos=771,384\n\
+Size=600,244\n\
+Collapsed=0\n\
+\n\
+[Window][Tuner]\n\
+Pos=725,230\n\
+Size=140,174\n\
+Collapsed=0\n\
+\n\
+[Window][Music Player]\n\
+Pos=704,243\n\
+Size=413,115\n\
+Collapsed=0\n\
+\n\
 [Docking][Data]\n\
 DockSpace             ID=0x8B93E3BD Window=0xA787BDB4 Pos=0,24 Size=1280,776 Split=Y Selected=0x6C01C512\n\
   DockNode            ID=0x00000001 Parent=0x8B93E3BD SizeRef=1280,217 Split=X Selected=0xF3094A52\n\