- moved constants GRAVITY_* from boot.php to Friendica\Model\Item
- also rewrote some array initialization:
From:
````
<?php
$arr = [];
$arr['foo'] = "FOO";
````
To:
````
<?php
$arr['foo'] = "FOO";
````
- added a few type-hints
* "post-type" replaces "bookmark" and "type"
* Removed some more type
* Added index to permission set
* The permission set is now stored
* The permission set is now removed upon expiry
* Post update now stores the permission set
* New file
* Permissions are now sorted
* Changed documentation
* Use "LEFT JOIN" to always fetch the item. Needed for update routines.
* New conversion routine that now covers every item
* Post update is now activated
* We now use a hash based upon RIPEMD-320 for content and activity
* The hash doesn't contain the plink anymore
* Legacy item fields are now "null"able
* New hash function for a server unique item hash
* Introduction of the legacy mode (usage of old item fields)
* Code simplification
* We don't need the "uri" fields anymore in item-activity and item-content
* Use the "created" and not the "received" date for the hash
* Avoiding several notices
* Some more warnings removed
* Improved uri-hash / Likes on Diaspora are now getting a creation date
* Corrected the post update version
* Ensure an unique uri-hash
* Don't delete orhaned item data at the moment
* Partly reworked, due to strange behaviour
* Some more parts reworked
* Using the uri currently seems to be more reliable
* Using the uri here as well
* Use the hash values again
* Grouped item fields in different categories
* Notices again
* use the gravity (we always should)
* Added hint for disabled post updates
* Notices ...
* Issue #5337: Personal notes are displayed again
* Use the gravity again
