camput: delete command, to send a delete claim

http://camlistore.org/issue/191

Change-Id: I053ab468420cc173e6122909bf3a0b16e4d43224
Merge "camput: delete command, to send a delete claim"
Intern blob.Refs in the in-memory Corpus.

For me, saves 419054 blob.Refs and 10 MB of memory.  Before/after:

Before:
Corpus stats: 159.057 MiB mem: 787886 blobs (88.853 GiB) (279308 schema (6073 permanode, 150557 file (111819 image), ...)

After:
Corpus stats: 149.884 MiB mem: 787886 blobs (88.853 GiB) (279308 schema (6073 permanode, 150557 file (111819 image), ...)

Change-Id: Idf71011c14d0d9b7457beab86dd084651fc3b122
Merge branch 'master' of https://camlistore.googlesource.com/camlistore
Reduce in-memory size of image info dimensions.

For my personal server,

Before:
Corpus stats: 149.884 MiB mem: 787886 blobs (88.853 GiB) (279308 schema (6073 permanode, 150557 file (111819 image), ...)

After:
Corpus stats: 145.172 MiB mem: 787886 blobs (88.853 GiB) (279308 schema (6073 permanode, 150557 file (111819 image), ...)

Change-Id: I47484e46b1eb70c8c4b5ee356cdcb0ceecde94e7
Shrink camtypes.BlobMeta a bit.  Saves 4 bytes of memory per blob.

For me,

Before:
Corpus stats: 148.859 MiB mem: 799465 blobs (89.487 GiB) (282303 schema (6478 permanode, 150962 file (112224 image), ...)

After:
Corpus stats: 146.559 MiB mem: 799465 blobs (89.487 GiB) (282303 schema (6478 permanode, 150962 file (112224 image), ...)

Change-Id: Id421dfc9d72c2a24c228418c01f9a3f05900c941
pkg/index: do not record a keySignerAttrValue on DelAttributeClaim

Change-Id: Ib1f81fe4879de2be7d484a5a40cc6bf0449893d5
Merge "pkg/index: do not record a keySignerAttrValue on DelAttributeClaim"
localdisk: faster enumerate.

still not as fast as possible, compared to native unix tools (find, ls, etc).
but closer.

Change-Id: I0add6bd07257f04f232332079214312297ec689b
Add new blobstore backend using Weed-FS

The main package is at pkg/blobserver/weedfs - modeled after pkg/blobserver/s3.

It uses some helpers for communicating with the Weed-FS master, in package
third_party/github.com/tgulacsi/weedfs-client. As this is only one http.go file,
maybe this could be incorporated in the weedfs package, as well.

Change-Id: I7940d47faabe63efb75c9e22b2d7715347092890