#13 font size choices not precise enough

[Ted Stodgell]

Bowser's preferences dialog only lets you choose the following font sizes:
6, 8, 9, 10, 11, 12, 14, 16, 18, 24, 36, 48, 72

I like Lucida Console at size 15 on a 1280x1024 screen, but there is no way to choose size 15 fonts.

The settings file seems to be a flattened BMessage. Why not use a textfile that users can edit themselves?

Alternatively, allow all integer fontsizes in the GUI dialog.

[Wade Majors]

i've added 15 to FontSizes[] in PrefFont.cpp, checked in.

we should probably work on a more elegant solution.