add APC

7php.com added to websites section

Added "Composer Checker".

Add ByteUnits library in 'Text and Numbers' section

Break out task runners into their own category.

Added Robo Task Runner

Added Anahkiasen Underscore library to Misc category

add xdebug and xhprof to code analysis

Fix the link to Sylius project

Project website is Sylius.org. :)

KLogger (https://github.com/katzgrau/KLogger)

add hrbridauth to thirdparty apis

Add Task to build tool section

I choose this name instead of just "Markdown" to make it more distinguishable.

Thanks fore mentioning it here, btw :)

Validating section: +1 PHP library

Added Securing PHP: Core Concepts

Remove trailing whitespaces

On PHP.ug you can find an overview of all PHP-Usergroups known to the maintainers. It's also the source of the usergoup-list on php.net/ug.php

Added Securing PHP: Core Concepts by Chris Cornutt to the book list.

Add PHPLOC to code analysis section

Fix a typo in README.md

Fix typo