New cask: track-o-bot

Track-o-Bot is a small, easy-to-use app which automatically tracks your
Hearthstones matches. Install, launch and you are ready to go.
Upgrade SourceTree.app to 2.0.2
Merge pull request #6546 from crainiarc/sourcetree

Upgrade SourceTree.app to 2.0.2
Update Mailbox to 0.3.12_141007
Update PG Commander to 1.5.2

Lowecase sha256
Add BBC iPlayer Downloads appcast
Update Genymotion to 2.3.0
Merge pull request #6547 from dlackty/mailbox-0312

Update Mailbox to 0.3.12_141007
Merge pull request #6551 from yachi/update_genymotion

Update Genymotion to 2.3.0
Merge pull request #6550 from glimpsed/patch-4

Add BBC iPlayer Downloads appcast
Merge pull request #6549 from scottrobertson/patch-2

Update PG Commander to 1.5.2
Add DataStax DevCenter.app v1.1
Merge pull request #6543 from res0nat0r/track-o-bot

New cask: track-o-bot
re-use version in track-o-bot
use underscore in some coconutbattery urls
remove stray trailing slash in golly url
doc re: fosshub and dropbox URLs

* fosshub URLs are blocked (per email correspondence)
  all similar providers cannot be used in Casks.
* shorten dropbox text
Merge pull request #6554 from rolandwalker/golly_trailing_slash

remove stray trailing slash in golly url
updated libreoffice to version 4.3.2
standardize Cask (capitalized) when used as noun

* was already done, but inconsistently
* this style follows homebrew Formula
* covers user-facing messages, test titles, comments
* some related minor orthography is included, such
  as the consistent spelling of our project name as
  "homebrew-cask"
* grammar nits