Tracking of Opponent Secrets (Friendly already worked as regular card plays)
Get mana cost of cards from local Hearthstone data and cache it
Disply mana cost if we can get it from the local cache
Allow tracking of revealed cards without a deck file
Some code tidy-up
fixes Bru7us/HS-DeckTrack#2
Merge branch 'master' of https://github.com/bru7us/HS-DeckTrack