actool: gzip application container image
changes metadata IP as per #132
metadatasvc: changed sha1 to sha256

Although HMAC with sha1 is less affected by collisions than sha1 alone I personally think it's better to use sha256 since the beginning.
This has also the advantage of automatically increasing the key sizei, for the HMAC function, from 160 bits to 256, which consequently increases the HMAC strength.
metadatasvc: wrapped initCrypto with log.Fatal

In case the HMAC key generation fails then do not allow the metadatasvc process execution to continue and print the error.
This avoids any potential security issues if there is not enough entropy in the system.
metadatasvc: checking the initCrypto error

Missed the real checking for the initCrypto error.
I have also taken the liberty to slightly change the printing of the error of the setupIPTables call to keep it consistant and use log.Fatal
metadatasvc: changed from fmt to log the setupIPTables

To keep the error handling consistant on the main function I changed the printing of the error from fmt + return to log.Fatal in the setupIPTables
appc/spec: clarify authors annotation
Merge pull request #141 from jonboulle/master

App Manifest authors format: wrong example?
README: Correct a few spellings/names
README: minor formatting tweaks

- Remove trailing whitespace
- Unwrap paragraphs, for consistency
appc/spec: remove duplicated line
appc: remove unnecessary bracket in README
Merge pull request #152 from azu/patch-1

appc: remove unnecessary bracket in README
*: remove historical RAF references
rkt: Adding missing new lines to the exit messages
Merge pull request #155 from rakyll/master

rkt: Adding missing new lines to the exit messages
appc/actool: only print output on success if debug=true
Update SPEC.md
added ubuntu trusty getting started guide
fix typo in ac-discovery spec