Improve sanitization
Add filters for config, sections and fields
Correct new filters
Make field filter work when no fields exist
Hide submit button when no fields exist in section
Add filter for specific section
Add prepare_sections method and improve section filtering
Rename plugin_file and plugin_dir
Add field data to custom_sanitize callback
Add page_hook_suffix
Re-add cpts_after_save action
Add .ctps-active-section-* to <body> for tabs
Restore original CSS and JS filenames