devscript: add `cask_namer`

This script implements naming rules for App-based Casks
as currently documented.  After some real-world testing, this
logic should be merged into `brew cask create`.  This commit adds
`doc/CASK_NAMING_REFERENCE.md`, and reduces `CONTRIBUTING.md` by
422 words.
add new CurlPostDownloadStrategy

- lib/cask/url.rb: initialize(): add new `:data` attribute to hold post parameters
- lib/cask/download.rb: perform(): dispatch to new class based on `:using => :post`
- lib/cask/download_strategy.rb: Cask::CurlPostDownloadStrategy:
  			extend curl_args with x-www-form-urlencoded data
- doc/CASK_LANGUAGE_REFERENCE.md: HTTP URLs: document new strategy
- test/cask/test_download_strategy.rb: Cask::CurlPostDownloadStrategy: test new strategy
Add uninstall stanza for Jawbone Updater
Add uninstall stanza for Lazarus
Merge pull request #3456 from alebcay/lazarus

Add uninstall stanza for Lazarus
Merge pull request #3431 from alebcay/jawbone-updater

Add uninstall stanza for Jawbone Updater
add `:quit` to jawbone updater uninstall
Add iTunes Scrobbler
devscripts: prefer GNU xargs

Apple-supplied xargs has bugs/limitations, especially
relevant to the -I flag
add Cask gambit-c.rb
Merge pull request #3455 from lowski/itunes-scrobbler

Add iTunes Scrobbler
updated postgres app to 9.3.3.0
Merge pull request #3461 from Anakros/postgresapp-9.3.3.0

updated postgres app to 9.3.3.0
Update YNAB to new version.
codekit.rb whitespace + sha256
Updated evasi0n cask to install v1.0.7
Merge pull request #3464 from poltak/evasi0n-1.0.7

Updated evasi0n cask to v1.0.7
Merge pull request #3462 from sigito/patch-1

Updated YNAB to 4.3.451.
Merge pull request #3458 from rolandwalker/jawbone_updater_uninstall

add `:quit` to jawbone updater uninstall
Merge pull request #3463 from rolandwalker/codekit_cleanup

codekit.rb whitespace + sha256