This has some TODOs still but I want to land it now anyway, and fix the
TODOs later.
* Add this.offsetMap which maps each linear model offset to a model tree node
* Refactor createNodesFromData()
** Rename it to buildSubtreeFromData()
** Have it build an offset map as well as a node subtree
** Have it set the root on the fake root node so that when the subtree
is attached to the main tree later, we don't get a rippling root
update all the way down
** Normalize the way the loop processes content, that way adding offsets
for content is easier
* Add rebuildNodes() which uses buildSubtreeFromData() to rebuild stuff
* Use rebuildNodes() in DocumentSynchronizer
* Use pushRebuild() in TransactionProcessor
* Optimize setRoot() for the case where the root is already set correctly
Change-Id: I8b827d0823c969e671615ddd06e5f1bd70e9d54c
To handle replace operations that are not themselves consistent (these
are common, for instance when replacing an opening element in one place,
then replacing the closing element somewhere else), we process
subsequent replace operations inside the first one until things are
balanced again, then issue a single rebuild for the whole thing.
Change-Id: Ide4613f046fabfeeef383138c39e350b1b710033
