Ditch yasnippets for PHP functions

I'm hoping a clever combination of auto-complete and php-auto-snippets
will give me something that's actually better than these.

I guess we'll see.
Add basic php-auto-yasnippets setup

I hope to get it to auto-trigger on selecting a function from the
auto-complete menu.

That will have to wait for a time other than 2 AM on a Sunday morning,
however, and may prove to just not be feasible.
Merge branch 'try-php-auto-snippets'

It seems to be working in its current state, so let's go with it for
now.

Admittedly, I may regret this when it's not almost 2 AM.