Version 1.57.1
--------------

- Closed bugs and merge requests:
 * Various maintenance [!279, Philip Chimento]
 * mainloop: Assign null to property instead of deleting [!280, Jason Hicks]
 * Added -d version note README.md [!282, Nauman Umer]
 * Extra help for debugger commands [#236, !283, Nauman Umer]
 * Crash in BoxedInstance when struct could not be allocated directly [#240,
   !285, Philip Chimento]
 * Cairo conversion bugs [!286, Philip Chimento]