Add 'deps' and 'requirements' methods to abstract classes
PHP CodeSniffer: Preserve config file on upgrades.
Adapt to recent change in drush formula.

Drush will now pick up the installed drush command automatically.

Offer an option to not have the command installed.
Add dependencies for --HEAD to abstract-php class

Closes issue #732
php53: fix issue with using --with-thread-safety

closes issue #962
php5*-gmagick: set path to graphicsmagick in configure script

Closes issue #1007
Fix brew audit warning messages
php*-opcache: v7.0.3
php5*-phalcon: v1.2.6
Add zookeeper extension
php5*-memcached: add support for sasl
Update php53-thrift.rb (+4 squashed commits)
Squashed commits:
[bc71b67] Update php54-thrift.rb
[c6f05a3] Update php56-thrift.rb
[d99c344] Update php55-thrift.rb
[a194129] Update php55-thrift.rb
Relies on an alternative versioned URL (+1 squashed commit)
Squashed commits:
[46ac292] PHPUnit-Skelgen (v1.2.1) new Formula
Added a formula to install phpunit-skelgen
Upgrade Envoy to 1.0.11
Foreman 1.0.0
update to wp-cli v0.14.1
Use block to declare HEAD dependencies

Going forward, declaring dependencies in a `head` block is preferred over checking `build.head?`. The same goes for devel and stable.
Switch from http: to https: (+2 squashed commits)
Squashed commits:
[0edd228] Added PHP 5.6 dependencies
[4c99e0a] Massive brew warnings fix
Bump PHP versions
Add optional phpdbg support to php 5.4 and above

Fixes issue #961