Move mod_exif.php options to config

[kaguy4]

Additionally, it makes more sense if imgops is enabled by default instead of the exif option

[anonwaha]

This isn't the only module with internal options instead of using the config files. Others are:

• mod_bbcode.php
• mod_captcha_old.php
• mod_pushpost.php
• mod_readonly.php
• mod_recaptcha_v2.php
• mod_rss.php