Correct output when browsing

[juliusHuelsmann]

When browsing while another command executes, the screen & buffer are filled incorrectly. Change that

• This can only be fixed if the schrollBack Patch is replaced by a better implementation; Ideally there is one large roundbuffer and the stuff currently displayed can be found in that roundbuffer at an offset.
  • There are to be distinct cursor positions for browsing and inserting.
  • in case the terminal width is resized, only increase the terminal buffer's width; when a terminal is resized after making it smaller, the content of the previous commands is not lost.
• port the current implementation to use the history patch that is created in the aforementioned task.

Patch developed here