Fix deprecation warnings with glib 2.58.

CID 276632

CID 276635

They're no longer needed since GTK+ 3.22 depends on Cairo >= 1.14

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.

Also fixes some memory leaks.

The link hint was truncated when the link rectangle was too small to
contain in. With this commit the link hint area is also redrawn.

Minor fixes include a rewording of "user size" to "unscaled size": Cairo
has user units, (unscaled) device units and (scaled) device pixels.

The document scale factors are now guaranteed to be non-zero.

A new Cairo helper function get_safe_device_factors() and a type
zathura_device_factors_t are introduced to simplify the code and avoid
some #ifdef blocks.

One can simply check the Cairo version now that GTK+ has been bumped to
3.10.

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>

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>

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

This patch resolves memory issues caused by using g_value_set_boolean and an
incorrect type of the target variable.

Thanks to edd@openbsd.org

All but the last jobs during zooming are aborted, so let smaller
jobs go faster.

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

Also emit the D-Bus signal

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

Also, turn on SyncTeX backward synchronization per default and remove -s option.
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>