Skins that use fonts other than VDR's standard "Osd", "Fix", and "Sml"
need to be adapted to use font names as understood by VDR's
CreateFont() (Family:Style as of writing this) instead of filenames in
their font attributes' names, to use '@' instead of ':' as the
separator before sizes, and have fonts shipped with the skin installed
and configured in fontconfig.  Typically, install font files (if
necessary) to a dir somewhere, run fc-cache(1) on the dir, replace for
example font="SomeFont.ttf:22,85" with font="Some Font@22,85" or
font="SomeFontBold.ttf:22,85" with font="Some Font:Bold@22,85" in the
*.skin file.  Also, in case the shipped fonts are derivatives of some
existing ones, they may need to be properly renamed to something so
they will be used instead of the original if it happens to be
installed. (closes #36)

- increased efficiency in drawing list items in the main menu
- introduce relative Pos and Size of objects to given BasePos, BaseSize
  (used to draw list items)
- increase skin file version to 1.1
- the position of list items is interpreted relative to the "list" container
  when file version >= 1.1
- when a position is specified for "block" elements, the position of all
  contained elements is interpreted relative to the container position
- selective update of changed objects
  refresh can be controlled for individual objects by the attributes
  "refresh" and "changed"
  default behaviour is to redraw everything (compatible with old skins)
- moved state tracking of marquee, blink, scroll from cText2SkinRender
  to cxObject
- fixed use of Update.Lock() in render.h
- new: dynamic width/height of objects
- new: Option "bgColor" used for items "Text", "Marquee", and "Blink".
- remember period to next timeout when doing a non-timeout refresh
  prevent occasional start/stop of marquee-text