Improvements on Album Art display

[imsamuka]

Re-implemented #54 on the dev branch. I'm sorry for not noticing the branch before... Also:

• Removed the copy-pasted code, and pointed the gompd to it's current master branch.
• Complied with the new cfg.PlayerAlbumArtSize.
• Created new cfg.PlayerAlbumArtDynamic to enable/disable the feature of dynamic sizing.

I don't know if re-doing the PR was the best idea, but i guess that works haha