[tlbuild] asymptote build

[John Bowman]

> MIME-Version: 1.0
> Date: Thu, 25 Jun 2009 11:53:03 +0100
> From: T T <t34www at googlemail.com>
> Cc: John Bowman <bowman at math.ualberta.ca>, kbrow1i at gmail.com, tlbuild at tug.org, 
> 	Karl Berry <karl at freefriends.org>
> Content-Type: text/plain; charset=ISO-8859-1
> 
> 2009/6/25 Angelo Graziosi <angelo.graziosi at alice.it>:
> > I have seen that on Cygwin, running
> >
> > $ asy.exe --version
> >
> > or something similar, creates the directory '.asy' in $USERPROFILE [1]
> > and not in $HOME! Is this the right thing?
> 
> This draws my immediate attention. Is there a way to redirect that
> .asy directory? We try to keep those things within our directory
> structure so it's easier to manage.

Outside of CYGWIN $USERPROFILE is the right place and until now,
we haven't need to check whether we are running in or outside of CYGWIN.
But we should be able to do that by checking for a CYGWIN environment
(variable or something like that) and then using $HOME just like under
UNIX. I'll give it a try..

-- John