torrc should allow runtime interpolation of some variables in filenames
nickm said in legacy/trac#2005:
> We should change our configuration file format so that we can get filenames with some
> variables that in them that are resolved at runtime. We already support that to some
> extent for filenames that start with ~ and ~uname on unix.
This is a feature request, as opposed to the documentation bug in legacy/trac#2005 so deserves its own ticket
issue