Book shows unsaved icon

and maybe the remotely-updated icon
Disable save button when saving
update the lastSeenSha when commit completes
remove Model.blobSha because remoteUpdater will not call reload models

because of something locally committed
pass options when implicitly calling removeChild
clean up some of the set() methods
refactor to introduce a "SmartCompositeView"
add ToC autosave
Merge pull request #20 from oerpub/phil-save-split

Add ToC autosave and do not refetch files after save