MFH: r439350 r439360 r441445

• Update to 4.7.4
• Switch to php7

Changelog:

https://wordpress.org/news/2017/04/wordpress-4-7-4/

Submitted by: maintainer via irc

• Revert the php7 switch, we can't force users to switch to php7 yet.

• Update the Wordpress ports to 4.7.5
• Changes: https://wordpress.org/news/2017/05/wordpress-4-7-5/

Approved by: miwi (mentor)
Security: http://vuxml.freebsd.org/freebsd/a5bb7ea0-3e58-11e7-94a2-00e04c1ea73d.html
Differential Revision: https://reviews.freebsd.org/D10848

Approved by: ports-secteam (myself)