v0.5.0-RC1

• admin page form not has novalidate attribute anymore.
• new page action hook: after_init_hooks
• new page action hook: after_init_fields
• new action hook: after_update_options
• the filter hook updated_options is now deprecated.
• new page filter hook: update_options (replacement for updated_options)

Full Changelog: v0.4.2...v0.5.0-RC1