While addressing a bug, I came across a instance of 'struct ast_datastore_info'
that was not declared 'const'. Since the API already expects them to be
'const', this patch changes the declarations of all existing instances
that were not already declared that way.
git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.8@370183 65c4cc65-6c06-0410-ace0-fbb531ad65f3