Show stats when bot is running

[martiGIT]

Hi! Thanks for your great work! It would be useful to see the stats (the same that are available while bot is stopped) on the screen "your bot is running". If it would be a problem to refresh it frequently - I think that updating it when bot reaches daily limit and goes to sleep for longer time would be enough. Thanks for you support Marcin

[mifi]

This shouldn't be too hard,but currently it could cause some concurrency issues (I think especially on Windows) because stats are stored in just a plain file. In the future should rewrite to use some kind of database which properly handles concurrency. Created a new issue #46