The ctrl-c hack used before didn't actually seem to work.
No haskell libraries expose TerminateProcess. I tried just calling it via
FFI, but got segfaults, probably to do with the wacky process handle not
being managed correctly. Moving it all into one C function worked.
This was hell. The EvilLinker hack was just final icing on the cake.
We all know what the cake was made of.
Fixed up a number of things that had worked around there not being a way to
get that.
Most notably, transfer info files on windows now include the process id,
since no locking is currently done. This means the file format varies
between windows and unix.
Would like to also have restart UI, but that's rather harder to do,
seems it'd need to start another copy of the webapp, and redirect the
browser to its new url, but running two assistants in the same repo at
the same time isn't good.
