add support for mu-plugins use
rename plugin class files to align with WP code style
modify antiforgery_id to use wp nonces instead of a GUID/UUID
lots of WordPress code style fixes
rework settings class to use magic getter, and a resolution hierarchy constant, db, default, null
secure all admin actions by using nonces
add GUI to support mu-plugins/constants
fix lots of phpdoc
lots of new documentation

Make antiforgery_id security configurable by adding AADSSO_NONCE_PASSES constant
- default nonce passes = 4

Add filters to add safe casting for CONSTANT setting values. i.e. string 'false' => boolean false
fix many doc comments
bump version to 1; huge new feature set and many breaking changes

…onstructor. Was possible to get_instance without init before.