Removing deprecated option - psr1_and_2

As matter of fact psr1_and_2 is deprecated in favor of the split psr1/psr2 options... I am removing this option (psr1_and_2) from the documentation. Eventually, I will remove this option from code. I haven't removed yet because I don't want to break the current installations. But on a later release, I shall drop it.

Closes sublime-phpfmt#16