changes in settings form and services for using standard Plugin::setAllSettings
updated every settings access
PDO bounded vars in queries where needed and removed mysql escapes
code clean up
Merged in geluzo/wolcms_registered_users/settings-integration (pull request #2)

Code renewal for settings and PDO ecosystem
Merge gh and bb

Conflicts:
	classes/RegisteredUsers.php
Rename RegisteredUsers.php to RegisteredUser.php