RocketInfo font size now configurable in option.  Small is 11, medium is 14, large is 17.

Corrected spelling on PrefChoiseSelector name, will get the translation keys some other time.
Added LineMetrics.descent to the line height for laying out the text in RocketInfo.
Merge pull request #216 from enderw88/Configure-design-window-font-size

RocketInfo font size now configurable in options.