Factor cache-probing logic out of buildfile.commit() and CmdRun().
Record added-tree sha256 in buildfile.CmdAdd, probe and use cache.
Add testcases for ADD caching, closes #880.
Add self to AUTHORS.
Add CHANGELOG.md entry for ADD caching.
fix progressbar in docker push
 Installation for FrugalWare
+ added missing link in index.rst
* some gramatic and spelling fixes

Thx jamtur :)
Update cross and tgz to play nicely together (creating a tgz for each supported OS/ARCH), and update release.sh to upload binaries and tgz files for all the supported OS/ARCH combos
Fixed #3039 - Added clarify on port options in API
Merge pull request #3340 from jamtur01/apiport

Fixed #3039 - Added clarification on port options in API
Merge pull request #3337 from tianon/release-darwin

Release tgz and binaries for cross-compiled platforms
Merge pull request #2809 from graydon/880-cache-ADD-commands-in-dockerfiles

Issue #880 - cache ADD commands in dockerfiles
small batch of edits/corrections to comments
Fix typo in devmapper error message
Document "name" query parameter for "POST /containers/create" in Remote API v1.8
Merge pull request #3348 from manuel-woelker/document-name-param-in-remote-api

Document "name" query parameter for "POST /containers/create" in Remote API v1.8
Merge pull request #3347 from smarterclayton/patch-1

Fix typo in devmapper error message
Merge pull request #3343 from bwiklund/comment-edits

small batch of edits/corrections to comments
Remove old debug from tarsum