If none of the gameboard images is set and and the user’s data
directory doesn’t contain a “zonebg” directory, create the directory,
copy contents from cockatrice’s app bundle and sets the config
accordingly.

Without this change, make install and make package would require “sudo”
under osx

By now tested on OSX only

Don't be a jerk when card database isn't usable.

Added Mac OS X build instructions.

Better error message and allow the user to still connect

Ref: #102

Mtgjson importer (fixes #84)

It will be saved only if:
* it’s different than the default (the user used a custom url);
* the download actually worked

By default oracle saves cards.xml to the correct path, where cockatrice
will be able to pick it up;
if oracle is not able to determine the path or the user unchecks the
option, oracle will ask for a save path

Merge branch 'mtgjson-importer' of https://github.com/Daenyth/Cockatrice into Daenyth-mtgjson-importer

Add HQ card option

Updated Windows build howto.

Windows MSVC support

This reverts commit 552a8e0c, reversing
changes made to d0f3ae6c.