bump crengine: support for partial rerenderings

Includes:
- Cache: minor simplifications
- Cache: improve cache file reproducibility
- CHM: minor cleanup
- LVStream: minor cleanups
- LVStream: fix and improve `LVZipDecodeStream` implementation
- LVStream: disable CRC checks for ZIP streams
- CSS: optimize :nth-child/of-type() and :nth-last-child/of-type()
- Page splitting: fix oversight in flags handling
- Update _doc_rendering_hash also when loading from cache
- getDocumentRenderingHash(extended): add parameter
- Toggable support for partial rerenderings of individual DocFragments
Also:
- util.isSubProcessDone(): add 'wait' option
- Also add getppid and some contants to ffi/posix.

base

@@ -1 +1 @@
-Subproject commit 08732afe1cd3c839a987713e4a500d65b520107e
+Subproject commit cea0a73556679b2d36fe9b8e9370b3377d785117