[Xastir-Dev] committed xastir shared files directory change

[Alan Crosswell]

At Curt's urging (he's been inhaling paint fumes too much:-) I've committed the 
previously-discussed changes to move the shared files directory from, for 
example, /usr/local/xastir to /usr/local/share/xastir (if you use the default 
--prefix with configure).

I've also added scripts/xastir-migrate.sh and scripts/xastir-fixcfg.sh.  The 
former should be run after make install.  It moves maps, etc. from the old place 
to the new place.  The later script fixes up a user's existing xastir.cfg to 
reflect the new locations.

Please test these changes *a lot* to make sure the migrate and fixcfg scripts do 
the right thing.  Make a backup of your maps first!

Once we are happy with the scripts, we can update the INSTALL and/or UPGRADE 
docs to add the steps to run the scripts.

Newbies to xastir will not need to run these scripts at all;  They are just a 
one-time transition tool for existing users.

As usual, these files will not show up for 24 hours or so.
/a