1, New character attribute
- Add the three shadow members to font
(width, color, location)
2, Painting
- Extract the shadow painting to a local function
and use that for character shadow (paintfrm.cxx)
- Reduce the painting rectangle of background
(shadow doesn't inherites the background of content)
3, Border merge
- Use text portion join members to skip shadow
when neccessary.
4, Vertical text
- Get shadow space dependant from oritentation and
border merge.
5, UNO API and ODF filter
Paragraph: ParaShadowFormat -> Character: CharShadowFormat

Change-Id: Ief4669990d238016c3ffc18a2609a3df7d9dddbf