Updates PHP version to 5.5.16 and removes some unnecessary packages
Changes the way PHP's mongo extension is installed

 The installation of the extension prompts the user about building it
 with Cyrus SASL support, making the provisioning process wait
 forever for the user input.

 Since pecl offers no way to skip this, the installation is now handled
 in two news tasks. First we check if the extension is installed and, if
 it is not, install it using the "yes" command to pipe a "no" to the input
 of pecl install.