NEW CODE: multiple file selection

[Nils Philippsen <nils rhlx01 rz fht-esslingen de>]

[ Cc:'ed to gtk-app-devel-list in case someone can use it, but beware - this
is rather untested and likely to change (hopefully, read below why) ]

Hello,

As some people might recall, I needed a possibility to select multiple files
at a time, read: a modified GtkFileSelection to shift-click, ctrl-click etc.

*drum roll* Half the job is done! (functionality, not integration, of course, 
but read further on)

I have made a new widget (GtkMFileSelection, read: multiple file selection),
which does just this:

- Looks like normal file selection
- Use control key to extend the current selection (without ctrl, the selection
  will be discarded)
- Use shift key to apply the last (un)selection to all files between the last
  (un)selected file and the file you clicked on
- Double clicking on a file now won't act like you clicked on "OK" (is this
  behaviour "expected", or should I have left this untouched?)
- The selected files can be retrieved with

  GList *gtk_mfile_selection_get_file_names(GtkMFileSelection *mfilesel);

  which is just a GList of gchar *. The list must be cleaned manually after
  use.

What needs to be done:

- Click'n'Drag behaviour should be implemented
- Not only because I had to rewrite/copy a lot of internal handling code of
  GtkCList/GtkFileSelection, this stuff _really_ belongs in GtkCList and
  GtkFileSelection: The shift-click, ctrl-click stuff in GtkCList, the option
  to select multiple files belongs into GtkFileSelection to avoid bloat and
  compatibility issues (i.e. if the implementation of those 2 widgets change).

I didn't attach the code to the mail, brave ones may get this from

ftp://rhlx01.rz.fht-esslingen.de/pub/gtk/gtkmfilesel-0.1.tar.gz

instead. The archive includes the code (which has stubs for persistent file
system browsing - I planned to implement having the selection  "surviving" a
directory change, but now I don't know if this is needed, so I might be
kicking this in the future), a test program and a Makefile, everything wrapped
in a separate directory for your convenience.

Comments on this would be very appreciated (especially on the issues of
coding, integration in the existing widgets and click'n'drag - still got none
to fewm clue how to implement this) - I tend to think I missed producing
optimal code at some points.

BTW: The copyright statement I added to the files is not for merits, it's
rather for the people to know whom to blame :-)

Bye, Nils
-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Nils Philippsen                  @college: nils@rhlx01.rz.fht-esslingen.de
Vogelsangstrasse 115             @home:    nils@wombat.dialup.fht-esslingen.de
D 70197 Stuttgart     -     clickety click     -     phone:    +49-711-6599405
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Wer heute an der Bildung spart,          Those who scrimp on education today,
hat morgen noch bloedere Politiker.      get even dumber politicians tomorrow.