Ref #127

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

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

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

* add multiverse id to cards.xml
* remove pictures urls from cards.xml
TBD:
* fix/clean oracle’s gui
* add support in cockatrice

Problem: Split card are imported as 2 different cards; need to find
some way to join them

Problem: Split card are imported as 2 different cards; need to find
some way to join them

* Remove cockatrice_HEADERS (obsoleted by automoc)
* Remove compilation flags definition and Qt4 finding calls
* Make use of CMAKE_INSTALL_PREFIX
* use INSTALL(TARGETS) in place of INSTALL(PROGRAM)
* Osx: create a proper application bundle
* Added comments