Lock abstraction (like the Cache)

- adding interface
- adding seperate drivers
- moving Lock to the Core package

src/Protocol/OStatus.php

@@ -19,7 +19,6 @@ use Friendica\Model\User;
 use Friendica\Network\Probe;
 use Friendica\Object\Image;
 use Friendica\Util\DateTimeFormat;
-use Friendica\Util\Lock;
 use Friendica\Util\Network;
 use Friendica\Util\XML;
 use dba;
@@ -513,9 +512,9 @@ class OStatus
 							logger("Item with uri ".$item["uri"]." is from a blocked contact.", LOGGER_DEBUG);
 						} else {
 							// We are having duplicated entries. Hopefully this solves it.
-							if (Lock::set('ostatus_process_item_insert')) {
+							if (Lock::acquireLock('ostatus_process_item_insert')) {
 								$ret = Item::insert($item);
-								Lock::remove('ostatus_process_item_insert');
+								Lock::releaseLock('ostatus_process_item_insert');
 								logger("Item with uri ".$item["uri"]." for user ".$importer["uid"].' stored. Return value: '.$ret);
 							} else {
 								$ret = Item::insert($item);