Added a reset view function to update display that clears search boxes and shows unconnected signals when the network updates
Made search filtering and unconnected filtering play better together. This involves a lot of deleting and redrawing of arrows, but this does not seem to noticeably slow the program, especially compared to actions like resizing, scrolling and drawing connections (when lots of arrows are present).
Added timeout to update display so that calls will be ignored within 100ms
Ad rate limit to the times update_arrows() can be called. A delay of 10ms is added, if the function is called within the delay, the first call is forgotten.
  Also, rows are hidden/shown based on model's connections/links, not on arrows (this is much more robust).
Optimized delays based on two screen refreshes. Removed redundant (and now unnecessary) call to update_arrows() in fliter_view()
Removed some debugging logs.