#12 Filelist should contain files, not directories

[Ulf Rompe]

Reason: If you have, for example, a directory
"/tmp/dir" containing a file "test.nef", then run
exigui like "exigui /tmp/dir", the file list will
contain this:

/tmp/dir

Then run a command like exiconvert that adds files to
this directory. the filelist will end up in showing this:

/tmp/dir
/tmp/dir/test.jpg

That's a bit confusing, even if it's not doing any harm
besides having the newly created files processed twice
in subsequent processings.

Just resolving dir contents on startup will solve this
inconsistency.