Added new options page to the NSIS installer.

The supplied (default) 'tuxpaint.cfg' is now empty, but is safely appended
to by the NSIS script. NSIS now has a Mode (Windowed|Full-Screen) and a
Resolution (640x480|800x600) option which append the following lines to
'tuxpaint.cfg':

fullscreen=$mode
nofancycursors=$mode
800x600=$res
[Where $mode and $res are "yes"|"no".]

The added file 'options.ini' contains the GUI layout for the new page.

visualc/options.ini

@@ -0,0 +1,59 @@
+[Settings]
+NumFields=6
+
+[Field 1]
+Type=LABEL
+Text=" Start Tux Paint with these options: "
+Left=0
+Right=-1
+Top=0
+Bottom=35
+
+[Field 2]
+Type=GroupBox
+Left=50
+Right=-50
+Top=36
+Bottom=78
+Text=" Display: "
+
+[Field 3]
+Type=LABEL
+Text=Mode:
+Left=58
+Right=100
+Top=46
+Bottom=55
+State=1
+Flags=NOTABSTOP
+
+[Field 4]
+Type=DROPLIST
+ListItems=Windowed|Full-Screen
+State=Full-Screen
+Left=115
+Right=-55
+Top=44
+Bottom=80
+Flags=NOTABSTOP
+
+[Field 5]
+Type=LABEL
+Text=Resolution:
+Left=58
+Right=100
+Top=62
+Bottom=71
+State=1
+Flags=NOTABSTOP
+
+[Field 6]
+Type=DROPLIST
+ListItems=640x480|800x600
+State=800x600
+Left=115
+Right=-55
+Top=60
+Bottom=96
+Flags=NOTABSTOP
+