snapshot-31

Menu bugs, dialog code update

The menu update caused snapshot 30 to crash on OS X 10.4 so I am
uploading this new snapshot in the hope that this bug will have been
fixed (I need some confirmation please).

However, there are some other new things in this snapshot as well:

- Dialog box handling has been updated.  This fixes a problem where the
  "swap file warning" dialog would pop up before the informational text
  in the editor window updated.  Hopefully this will also cure various
  other problems with dialogs (e.g. nothing happening when opening files
  from a dialog box).

- Added dock menu with "New Window" item.  This is useful with "Spaces"
  on OS X 10.5 since you can use this menu to open a new MacVim window
  on any "space" when another editor window is already open.  (Also, now
  there is always a way to open a new window, even if the menus are
  customized, or if "-u NONE" is used.)

- I have started trying to fix "modeless selection" and it sort of works
  on my machine, but I've had one report stating that its not quite
  working so you mileage may vary.  Make sure to let me know what works
  and doesn't so that I can fix this properly.  (Try selecting text from
  the command line.)

- The default font (DejaVu Sans Mono) has been updated to version 2.25.

- Latest Vim source code merged.

Finally, this snapshot was compiled on OS X 10.4 PPC since there were
reports that the snapshots I compiled on 10.5 Intel had some problems.
I managed to include Ruby and Python support, please test it to make
sure it actually works (I don't use either of those).