Fix switch indentation with multiple cases

This fixes issue #186 where indentation was incorrect for statements
following multiple case labels that switch on true/false/null or strings
delimited by double quotes.

Signed-off-by: Eric James Michael Ritz <ejmr@plutono.com>
Disallow visibility keywords in colon labels

Trivial change; a construct like 'public:' does not exist in PHP, so
don't explicitly allow it in c-nonlabel-token-key.

Signed-off-by: Eric James Michael Ritz <ejmr@plutono.com>
Update PHP Mode for version 1.15.0

Special thanks to Joris Steyn, whose patches are single-handedly
responsible for this release.