page: Hide new pages by default
- page: Fix rowSpacing for EditablePage contents
I don't really know why this suddenly started failing but it did. In any case, we don't need to rely on this being passed down from the Loader in the first place, as the expression is simple enough.
- page: Replace EditablePage's OpacityAnimator with NumberAnimation
OpacityAnimator has strange side effects such as continuous redraws. Normal animations do not have that effect, so use those instead to avoid these sideffects.
- page: Hide new pages by default
We load pages on request but also in the background if a page requests it. The background loaded pages would be considered visible, resulting in anything relying on said visibility to continue running, such as animations of BusyIndicator. This consequently results in continuous redraws.