Update php syntax support

Summary:
This is now mostly based on the official php documentation, with
some minor exceptions. This should make it easier to keep both
in sync in the future.

Based on phpdoc svn revision 346409.

Reviewers: dhaumann

Reviewed By: dhaumann

Subscribers: dhaumann, kwrite-devel, kde-frameworks-devel

Tags: Kate, Frameworks

Differential Revision: https://phabricator.kde.org/D17990