[Ada-mode-users] Minor GPR-related problems & fixes

[Simon Wright]

I just pushed changes for these two problems to MTN, branch 
org.emacs.ada-mode.sjw:

(1) An attribute in a GPR can contain an others choice:

   package Builder is
      for Switches (others) use ("--create-map-file");
   end Builder;

(2) gpr-query.el needs to take account of filesystem case-insensivity for 
Darwin as well as Windows.