Bug 435922 - PHP 5.6 support

Conflicts:
	plugins/org.eclipse.php.core/src/org/eclipse/php/internal/core/codeassist/PHPSelectionEngine.java
	plugins/org.eclipse.php.ui/src/org/eclipse/php/internal/ui/preferences/PHPVersionConfigurationBlock.java

Change-Id: I5933c027352071cab2a8dc79060a1f82f819df77