Feature: Implement saving output history.
Bugfix: fix watching/reloading files with syntax errors

  -- the syntax errors never got a chance to be output to the
     console, since, the signal that changing to a directory finished
     returned after the signal to run the script and the console
     went into editing mode too early. For now we delete the assert,
     but in the future a better solution should be found.
Added kdevelop files and vim/kate swap files to .gitignore.