Size of document settings dialog

[Pavel Sanda]

Hi,

the document settings dialog quite grew in vertical size for 2.4 mainly due to the
formats pane and I think we should shrink it back.

I see several options:
  1) create tabbed pane for docbook/xhtml(and perhaps TeX)
  2) Move content of "LyX Format" to "Output format" (not conceptually clean but would
     work if properly rephrased e.g. "Save transient properties into LyX format").
  3) Create completely new pane (not sure about new grouping though)
  4) Introducing scrollbars?

I'd prefer 2), but mostly due to my laziness :)

Opinions/preferences?

Pavel