Add a way to change the font size for code views

Using my 13" MacBook Air at its native resolution, the code font is just too small. (It must be even smaller on an 11" MacBook Air.) It would be great if there was a way to make it bigger. Ideally I could press the standard ⌘-T to open the standard font panel, and adjustments there would take effect instantly; and ⌘-= to increase the font size; and ⌘— to decrease the font size.
