Settings Form Expanded Search

Fixed this undocumented issue:
![BoldFontCutsOffText](https://f.cloud.github.com/assets/1484018/109764/78ff0b74-6a96-11e2-951a-04e17728a389.png)

Also, used recursion to add all child controls' [`Control.Text`](http://msdn.microsoft.com/en-us/library/system.windows.forms.control.text%28v=vs.100%29.aspx) property to list of searchable strings.
![BoldFontCutsOffTextFixed](https://f.cloud.github.com/assets/1484018/109780/d34c4fc8-6a97-11e2-9c19-42a6b8f29e7a.png)

I think it would be optimal to implement some sort of caching on the search strings, because each settings sub-page is recreated every time the Settings Form is shown.

However, the [`MemoryCache`](http://msdn.microsoft.com/en-us/library/system.runtime.caching.memorycache%28v=vs.100%29.aspx) is outside of the .NET 4.0 _Client_ Profile.