Current version is 0.13-2

* Changes since version 0.13:
  - fixed a keybinding in the 

* Changes since Version 0.12:
  - added rudimentary support for exporting images
  - raise control panel using 'p' key
  - some fixes to convergence testing and command line arguments

* Changes since Version 0.11:

  - added some special plots: derivative, subtract A-B, convergence exponent
  - added ability to set axis ranges from the command line and plot window
  - cured various seg-faults
  - introduced various new seg-faults