* main.cpp: removed path checking and db loading
 * card database: merge card loading methods into a single one
 * settings cache: take care of returning safe paths for decks,
replays, etc..
 * main window: if db loading fails (eg. first run), propose to run
oracle

NSIS: propose to run cockatrice instead of oracle

Rework card database loading

 * Move carddatabase-related method out of deckeditor tab
 * Load cards in another thread and render them progressively
 * Optimize database reload after enabled sets change

Fix deck editor column width

 * removed the noCard hack.
 * getCard() no more creates cards instead of just returning existing
ones
 * Fix the “edit tokens” dialog.
 * PictureLoader: avoid trying to download twice the same card
 * PictureLoader: correct return of card background
 * AbstractCardItem: avoid recalculating card color at every paint

Use a different file to save custom tokens

Misc required improvements

 * Use nullptr;
 * Refactor CardInfoWidget to use CardInfoPicture and CardInfoText
instead of duplicating code;
 * Added CardInfo::getColorChar()
 * Fixed some potential crashes
 * removed dead code related to CardInfoWidget
 * Don't require a restart after adding a new custom sets file
 * Bump CMake requirements to 3.1

 * Removed remaining picture handling from card database and cardinfo
 * removed the “noCard object” hack

fixes #1520

Moved setting files & Added code for a future portable build

As per @daenyth’s comment:
https://github.com/Cockatrice/Cockatrice/pull/792#issuecomment-76593730

This is the first implementation of a theme manager. It’s a rebased and
revisited version of #792.

After adding a card to the main or side, the search text will become
selected to easily start the next search

fixed welcome msg
added some articles
added database phrase to card updater
cosmetic changes to the description in edit sets

As per @daenyth’s comment:
https://github.com/Cockatrice/Cockatrice/pull/792#issuecomment-76593730

This is the first implementation of a theme manager. It’s a rebased and
revisited version of #792.