New stable PHP version released (5.6)

http://php.net/archive/2014.php#id2014-08-28-1
updated to PHP 5.6 in getting started chapter
books and PHP 6 updates
Merge pull request #428 from peterkokot/patch-1

Updated to PHP 5.6 in getting started chapter
Merge pull request #429 from FranciscoP/patch-1

New stable PHP version released (5.6)
Merge pull request #430 from peterkokot/patch-php7

Books and PHP 6 updates
Merge remote-tracking branch 'upstream/gh-pages' into gh-pages