Transfer more gtk-xt code, and add some new

Transfer more gtk-xt code, and add some new

Add input-source handling
Graft color picker (<Enter> callbeack in the text field is still missing!)
Handle contents of label widgets (store handles in Option for access)
Add printing of clocks
Add printing of window title
Pay attention to BORDER attribute of Label Options (pack in frame)
Delete ReadBitmap code (also remove #including of bitmap files for icons)
Fix layout of textviews (adapt to newer Option format, incl. wrap, scroll)
Support vertical stacking in Break Option (no table widening when !SAME_ROW)
Make default horizontal scroll policy automatic (for engine-output window)
Fix disabling of unused spinners in TC dialog