Further enhancements to PHP indentation

[adriaanzon]

I simplified the indentation rule for detecting <?php. It seems to work better now when there's a <?php block at the beginning of a file.

searchpair() now skips matches that are inside a string or comment.

I also removed the unneeded conditional i mentioned here.

[adriaanzon]

The check for a string or comment seems really slow if you try to indent larger files.

Edit: I removed that commit for now.

[jwalton512]

Thanks!