Run composer installer with PHP

The composer installer has to be executed with PHP itself as detailed on
https://getcomposer.org/download/.

Only add ppa if it doesn't exist.

This comit is in addition to pull request #70. The add-apt-repository command
will only be run when the ppa has not yet been added.

Added the php-mail package for Debian

Manually add php PPA in UTF-8 locale [Resolves #69]

changed Debian hhvm PID filepath to match default /etc/init.d/hhvm PID filepath

manage xcache.ini in pillar

use False as default, and test boolean, rather than none

Sort keys per section within php.ini.

alphabetically

Fix install-composer edge cases

Recursively merge php.ini options

Add hhvm support to php ng formula

In order to reuse the default structure of this formula
I changed the config a little bit to configure hhvm files.

Fix Debian package name for `php.ng.xml` state

Update Composer state file to not use curl

Add support for GMP ext

Use iteritems() instead of items().

Signed-off-by: René Jochum <rene@jochums.at>

XML module is already built-in. In any case, `php5-xmlrpc` package actually provides XML-RPC module.

Allow pillars to specify a list of extensions

Add php.ng.xsl for Debian

Add support for Arch Linux

install php5-oauth in php.ng.style

add php.ng.geoip, php.ng.pspell, php.ng.xdebug for Debian