[MLton] Subversion

[Matthew Fluet]

> MLton now officially uses a Subversion repository.  

I note that the conversion successfully propagated the .cvsignore files
into the svn:ignore property.  I imagine that we can now delete all the
.cvsignore files;  however, bin/clean looks for a .cvsignore file to
determine what to delete at a directory cleaning.  It does not seem wise
to require Subversion (and all the .svn directories) for 'make clean' of a
released source package.

Perhaps there is some way of ensuring that the value of the svn:ignore 
property is always exported to a .ignore file?  Alternatively, we could 
push all the ignored files into the appropriate Makefiles in the clean 
target.