page header in scroll mode + tts

[teleshoes]

also fixes #326

[teleshoes]

@buggins @plotn
TL/DR there is no bug here that i am aware of, and this pull request can be merged as-is, without regression, to the best of my knowledge.

this PR fixes a bug (animation in scroll mode) and implements an unexpectedly missing feature (title bar ignored in scroll mode). with this PR, titleBar/pageHeader/pageFooter works consistently and correctly in scroll mode and page mode, at the top or bottom, with or without animation, and in portrait or landscape

before this PR, titleBar was ignored in scroll mode, and animations in scroll mode were buggy.

notes:

1. you cannot see the scroll-mode page footer (at the bottom) in TTS mode, because the android navigation bar covers it. this is already the case in page mode when you show the android navigation bar. i think the best solution to always show the title bar would be to just hide the navigation bar in TTS, but that is a completely separate issue.
2. the animation includes the title bar, like it does in page mode. if this is visually unappealing, an alternative can be implemented, in both page and scroll mode, but it is unrelated to this pull request.