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Changes between Version 15 and Version 16 of TEXT_LAYOUT_LAZY

v15	v16
110	110	* The PagePreviewPalette has some problems with repainting. However, this does not concern the text layout, nor the text layout is the reason for this behavior. The problem is that when an area layout is recomputed, it is not redrawn. I doubt this is an issue, since we do not guarantee the PPP will display the exact content of a page.
111	111	* The background thread only calls a HotLayout's method. The only performance problems it could have (in my opinion) is, that it could iterate infinitely. Therefore I created a test (linked in the design section), which asserts the thread does not deliver unneeded results. When no work is required, the thread waits blocked. On the other side, every head text frame has exactly one background thread (not like in the auto-chaining), Which I think is OK.
	112	* The auto-chain invocation and background-thread one have been put in a ResourceProperty, I think this makes the design more clear and it is now visible when and why these thread work.
112	113
113	114	* Just a note, please do not forget that this ticket should be integrated in the [svn://sophie2.org/sophie2/branches/private/kyli/sophie2-text] branch.