Update to make all class E_NOTICE safe, add page_content

- ALL classes are E_NOTICE safe as far as possible.
There might be some minor things left over which will be cleaned up in
further testing

- Added declare(strict_types=1); on all pages for trying to make all
calls strict

- Added page_content sub content to edit_page, with this some inner page
content with ACL can be set, eg for use with Ajax/JS calls with backend.
Also alias can be set so the control ajax pages can back reference to
the master page content setting. Currently only one back reference is
allowed

- Note that the PAGES array has no numeric indexes, but uses the cuid as
index

4dev/database/table/edit_page_content.sql

@@ -0,0 +1,20 @@
+-- AUTHOR: Clemens Schwaighofer
+-- DATE: 2019/9/9
+-- DESCRIPTION:
+-- sub content to one page with additional edit access right set
+-- can be eg JS content groups on one page
+-- TABLE: edit_page_content
+-- HISTORY:
+
+-- DROP TABLE edit_page_content;
+CREATE TABLE edit_page_content (
+	edit_page_content_id	SERIAL PRIMARY KEY,
+	edit_page_id	INT NOT NULL,
+	edit_access_right_id	INT NOT NULL,
+	name	VARCHAR,
+	uid	VARCHAR UNIQUE,
+	order_number INT NOT NULL,
+	online	SMALLINT NOT NULL DEFAULT 0,
+	FOREIGN KEY (edit_access_right_id) REFERENCES edit_access_right (edit_access_right_id) MATCH FULL ON DELETE CASCADE ON UPDATE CASCADE,
+	FOREIGN KEY (edit_page_id) REFERENCES edit_page (edit_page_id) MATCH FULL ON DELETE CASCADE ON UPDATE CASCADE
+) INHERITS (edit_generic) WITHOUT OIDS;