Display operation progress in the main UI

[zymos]

First: the box that displays "Done", when transfer is complete needs to reset when a second transfer is performed.

Second: It would be nice for the main window to display the progress of operations, similar to what is displayed in stdout on terminal. but maybe less technical

[sole]

Thanks for the ideas!
Feel free to implement some because I don't have time to do it myself nowadays ;-)
I'll be happy to merge.

Also-I'll suggest you open a new bug per feature, so it's easier to

1. track them down
2. assign/take them
3. resolve them

[sole]

done in #59