Fixed blacklist not working when empty (because, `exists` is true if the list is empty...)
Fixed pure userdata being left on the stack during synchronized calls, potentially leading to unpersistable states.
Made HTTP requests not use userdata, instead the handle it returns can now be used the same way as sockets (except it can't be written to).
Disabled userdata for the time being, looks like it will need some major time investment to track down that crash...
Removed active GC before resuming states, since that could cause execution of user code (__gc metamethod), and sandboxed __gc metamethod some more.
Got rid of the 'magic pixel' in the font texture.
Added screen.getKeyboards() to allow listing keyboards attached to a screen.
Generating new random key for special persistence whenever a computer is started, making it pretty much impossible for users to inject custom code into the persistence logic.
Fixed font texture.
Updated SGT2 API.