At the moment, rox-filer determines whether a given
file is "hidden" by checking whether its name starts
with a dot. This patch allows the user to specify a
regular expression for hidden files; any file matching
this expression will be considered "hidden". The
default expression is "^\\." (checks whether the name
starts with a dot).
Rationale: many applications (compilers, latex, etc.)
generate a lot of files which are, most of the time, of
no interest to the user (log files, intermediate files,
etc.). They just clutter the picture of the directory
in the same way as normal hidden files do. This patch
allows the user to suppress display of those files. As
opposed to the filtering option, the user can see all
the files simply by pressing the "show hidden files"