Reorganizing images
Improving layout
Adding timer to show how many seconds have passed since last update
Adding tooltips to show last update and last fetch date for each symbol
Improving how errors are shown and cleared when exchange/symbol specific
Fixing error handling in streamers
Adding a button to collape/expand symbols

Collapsing/expanding single exchanges not supported. State is not
preserved, on next reload all symbols will be expanded
Splitting quotes layout in two main columns
Adding GitHub project buttons
Adding new details pane for each symbol/exchange
Aborting streaming notifications when there are no listeners left
Updating individual timers
Converting timdeltas tu human-readable format
Minor improvement
Merge branch 'improve-ui'
Adding support for USDARSCL and USDARSBOL