First batch of 5.6 migration guides updates for beta 1.

I'm still working on this, and expect to commit a bunch more changes tomorrow,
but I get nervous when I have changes sitting locally for too long.


git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@333035 c90b9560-bf6c-de11-be94-00142212c4b1