(Suggestion) Restore writethings

Object place is very useful for mappers, but ever since the command "writethigs" got disabled it's been about as useful as Sonic 2's debug mode in the final release.

But what if the command was brought back?

In Binary maps it could just write the normal things lump as usual, but in UDMF maps it could instead write a new TEXTMAP lump to the SRB2 install directory.

At the very least maybe implement it for UDMF and if it's not possible for Binary maps anymore, have it popup a message about it not working in binary anymore.