Made PageRef an actual reference

Signed-off-by: Wilson Brenna <wbrenna@uwaterloo.ca>
Fixed two off-by-one errors

Signed-off-by: Wilson Brenna <wbrenna@uwaterloo.ca>
Changed event handling

The UndoActions now fire events whenever content changes.
The PageViews receive the events and rerender themselves.

Signed-off-by: Wilson Brenna <wbrenna@uwaterloo.ca>
Fixed Stroke error.
Merge branch 'master' into addpoppler
Merge branch 'addpoppler' into glib_new
Fixes redraw bug on firePageChanged.
Merge branch 'master' into addpoppler
Merge branch 'addpoppler' into glib_new
Require glib>2.32.0