goexif: merge upstream and document process.

This commit contains changes following the process documented in the new file
README.camlistore.  Because we've used such and ad-hoc process managing this
directory in the past, we will need a followup commit that manually merges
changes that failed during 'git am'.

This change passes 'make presubmit' and a quick examination by running 'devcam
server' 'devcam put'ing some CR2 files and visiting /ui/.

camlistored logs some messages like:
	2013/10/13 13:55:11 filename "RAW_CANON_50D.CR2" exif = 2008-09-17 15:13:40 +0000 UTC, <nil>
	2013/10/13 13:55:11 filename "RAW_CANON_5DMARK2_PREPROD.CR2" exif = 2008-10-29 20:05:00 +0000 UTC, <nil>

And thumbnails are properly rotated in the web ui.

commit 6034d9ed8d1fd31a8b7e80ffe4acc2c47b3ffd25
Author: Bill Thiede <git@xinu.tv>
Date:   Sun Sep 15 15:10:39 2013 -0700

    Add support for TIFF based images, like CR2.

    This adds detection for TIFF images and skips the steps of removing JPEG and
    EXIF headers from the data before calling tiff.Decode.

commit 2cc61b08a74f782b8665442ee5977649d3109971
Author: mewmew <random0x00@gmail.com>
Date:   Sat Jan 26 22:38:20 2013 +0100

    tiff: Fix bug in convertVals, where floatVals was allocated more than once.

commit 8206b5bee50e1d6d7e3b6b385e4ef0ef6e029137
Author: Robert Carlsen <rwcarlsen@gmail.com>
Date:   Wed Jan 23 15:08:48 2013 -0600

    vetted fix from Fatal to Fatalf

commit 4347b209f9f0396dd2cca9dbf25cb7f519148ec4
Author: Robert Carlsen <rwcarlsen@gmail.com>
Date:   Thu Jan 10 20:07:05 2013 -0600

    analytics

Change-Id: If13a7dbacd35ee2a49315bacf2d7cfc7795c0cc2
importer: initialize Host's search handler and blobserver target

Change-Id: I482e6f192620c254648b19b3044eedbd44de288c
Merge branch 'master' of https://camlistore.googlesource.com/camlistore
importer: add accessors for Target and Search handler

Change-Id: I49cd2a1fc08547eada21cee1506f190fe8f6d6de
schema: clarify that WriteFileFromReader's filename is optional

Change-Id: I0df3783b282492db1dac29ed3c07e9a38df30a5e
importer: partial API sketch.

Change-Id: I05adf61164e4aabca35a1bb0ff1f0c8c0fd34ef1
Merge branch 'master' of https://camlistore.googlesource.com/camlistore into media
script to generate contributors page from git shortlog.

http://camlistore.org/issue/15

Change-Id: I670e19424772530b190326ba125fdf1122ff29af
localhost auth: resolve localhost to [::1] if using ipv6

http://camlistore.org/issue/238

Change-Id: Icab7d87fe651365fb44db4c2874d4976fa631ad6
Merge "localhost auth: resolve localhost to [::1] if using ipv6"
auth: maybe fix IPv6 test on IPv6-less Linux

Change-Id: I438388420854014e862587960bc549fbcc8f3f2d
localdisk: fix TestPaths on Windows
auth: don't fail IPv6 test if host can't resolve localhost to [::1]

Change-Id: I3eade17e593da67d33be86563fe179ac6464c561
Merge "auth: don't fail IPv6 test if host can't resolve localhost to [::1]"
Merge branch 'master' of https://camlistore.googlesource.com/camlistore into media
wip

Change-Id: I7cdafbd53b59fc53dafa4c19aa391f51f6982061
Merge "script to generate contributors page from git shortlog."
jsonsign: add missing Close on public key blob reader

Change-Id: I1837fe65433e3a713939ae178e278f52884ab114
Merge branch 'master' of https://camlistore.googlesource.com/camlistore
schema: integrate with the jsonsign package.

Signing schema blobs (permanodes and claims) was too hard before, and
the code was scattered in weird places.

The pkg/jsonsign code tries pretty hard to be Camlistore-neutral, so
it remains so.

The pkg/client code (which deals mostly with HTTP access to a remote
camlistore server) had the signing the logic in it before, mostly
because that's where we originally needed it (for camput), but that
should be fixed in subsequent changes, to remove most of its signing
logic and use pkg/schema's instead.

The schema package now depends on jsonsign, which I think is an
acceptable dependency edge, since the Camlistore schema does logically
depend no signed claims (and that was a gaping hole in its public
API), and it seems safe cyclic-wise, especially if jsonsign continues
to be a leaf package.

Change-Id: I10229ec5d880ddd801cb1ba77ac26b654693036d