app-container: update SPEC on filesets

Originally we thought that this would be used for making correctly
hashed ACI reassembly possible but we realized that if you are storing
the on-disk ACI then you can also store the ordered list too; for later
verification against a key.
Fix broken link to the container spec.
Merge pull request #122 from DanLipsitt/patch-1

Fix broken link to the container spec.
Simple typo fix.
Merge pull request #124 from sbevington/master

appc/spec: fix typo
Merge pull request #121 from philips/clarify-appc-fileset-files-list

app-container: update SPEC on filesets
Fix small typo
Merge pull request #125 from antoinerg/patch-1

appc: fix small typo in hash schema
Fix typo in README.md
Merge pull request #128 from ankushagarwal/readme_typo

Fix typo in README.md
stage0: stream image to avoid extra copy
fix json typos
Merge pull request #130 from MarkKropf/patch-1

appc/spec: fix json typos
pkg/tarheader: vet fix

Fix the following vet report:
  - pkg/tarheader/pop_darwin.go:1: +build comment must appear before package clause and be followed by a blank line
Merge pull request #131 from ceh/vet-fix

pkg/tarheader: vet fix
Update SPEC.md

Removes duplicate 'the' in logging section.
Merge pull request #137 from lamielle/patch-1

appc/spec: fix typo
Merge pull request #129 from jonboulle/master

stage0: stream image to avoid extra copy
appc/spec: clarify authors annotation
Merge pull request #141 from jonboulle/master

App Manifest authors format: wrong example?