Replace scale with zoom in most cases. Scale means pixels per point, as
before. The zoom is the screen-size / document-size ratio: a zoom of 1
means that the document should have the same size on screen as on paper.

This fixes many issues with the previous DPI changes, e.g. with link and
search rectangles.

Signed-off-by: Sebastian Ramacher <sebastian+dev@ramacher.at>

Signed-off-by: Sebastian Ramacher <sebastian+dev@ramacher.at>

Signed-off-by: Sebastian Ramacher <sebastian+dev@ramacher.at>

Signed-off-by: Sebastian Ramacher <sebastian+dev@ramacher.at>

This patch implements two new ZathuraDatabaseInterface functions, save_jumplist
and load_jumplist, for both the plain and sqlite backends (along with some
cleanups).
Signed-off-by: Sebastian Ramacher <sebastian+dev@ramacher.at>

Signed-off-by: Sebastian Ramacher <sebastian+dev@ramacher.at>

Thanks to J. Commelin for the patch.

We need to know the document's 'scale' value earlier (before cairo
surfaces are created). Otherwise, cairo surfaces will be re-created and
wrong page will be rendered (since zoom doesn't preserve page number).
Signed-off-by: Pavel Borzenkov <pavel.borzenkov@gmail.com>
Signed-off-by: Sebastian Ramacher <s.ramacher@gmx.at>