renamed CardInfo to CardDownloadData
refactoring to CardImageSource
removed Card dependency for image downloading
Merge pull request #249 from Noahsark/master

fix a bug causes npe.
Added a sound playing if human player joins a match.
Added DrawDiscardTargetEffect, improved DrawDiscardControllerEffect.
[Minor] Some rework of DrawDiscard effects.
[Minor] Formatting.
[MMA] Added 2 cards. [TMP] Added 1 card.
Added some background images to client/backgrounds.
* Binding Angel - Fixed the bug, that the "skip next combat phase" ability did not work.
Set the server release log level property to warn.
* UnearthAbility - Fixed that unearthed creatures had no haste.
Added Brackwater Elemental, Kathari Momber.
* Added DelveAbility.
[MMA] Added 6 cards.
* InfectAbility - Added reminder text.
* Mirran Spy - Added the missing flying ability.
* Conversion Chamber - Fixed the exile artifact handling that's now an effect and the effect can target artifacts in any graveyard.
* Ogre Menial - Added the missing infect ability.