Moved global PAGE_* to Profile class (#5500)

* Rewrites:
- moved PAGE_* to Friendica\Model\Profile class

* Fixed more rewrites from plain (global namespace) PAGE_* to Friendica\Models\Profile class

* CR request:
- moved all PAGE_* constants to Friendica\Model\Contact class
- fixed all references of both classes

* CR request:
- moved ACCOUNT_TYPE_* constants from boot.php to Contact::ACCOUNT_TYPE_*

* Just copy-pasted this code from boot.php, needs to be changed to `const ACCOUNT_TYPE_FOO = x;`

* Ops, melting brain cells here ... :-/

include/security.php

@@ -245,7 +245,7 @@ function can_write_wall($owner)
 				intval($cid),
 				intval(Contact::SHARING),
 				intval(Contact::FRIEND),
-				intval(PAGE_COMMUNITY)
+				intval(Contact::PAGE_COMMUNITY)
 			);
 
 			if (DBA::isResult($r)) {