Fixed small poster sizing for shows view

Migrated misc css classes to bootstrap 4

Added timeout for logins to match expire_in of tokens
Fixed resetting of app_id when resetting config to defaults

Main shows page posters migrated to bootstrap 4 cards

Upgraded to Bootstrap 4.x
Merged misc icons into core icon pack

Added ability to unlink account from app
Fixed issue with scheduler view and empty show runtime
Replaced all no16 and yes16 with font awesome equivalents