index: start of re-indexing smartly when dependent blobs are missing

See https://camlistore.org/issue/102

Change-Id: Ia5f69475d8f47398bc228a96e7694d59edf277bf
Merge branch 'master' of https://camlistore.googlesource.com/camlistore
Adds camlistore.Spinner, a progress meter based on the safe icon.

This isn't used by anything yet, but will be used in subsequent changes.

Change-Id: I0bd3174b2e16f8cab814ce72425b5fa1fed8d07e
Merge "Adds camlistore.Spinner, a progress meter based on the safe icon."
When updating spinner, don't relayout entire doc

Change-Id: I004e691e015b8a5e64f95702dc1f08ac75c91c0f
Finish implementing storagetest

Add use into localdisk (diskpacked already uses it).
Add ErrNotImplemented error for blobserver and mention the possibility
for RemoveBlobs (diskpacked deficit).

Change-Id: I6a50f263a58c8d3d1611ff9a060ea9fa4aee6163