anchor.diff:   * Exit when Graphviz is not found
    * Disallow to re-open goal atop of the closed one
    * Fix: goal deletion may cause failure on the next startup
  - * Fix: migrations did not run for existing DB #2
  + * Fix: migrations did not run for existing DB https://github.com/ahitrin/SiebenApp/issues/2[#2]
    * Improve selection UX: avoid buffer overflow
   
   Other improvements:
  
positive.code: New features:
  
  * Open another file in the same window (no Github ticket, LOL)
  * Restore export into .dot format #94 (in a new `sieben-manage` script)
  
  Bug fixes:
  
  * Zoom: inconsistent behavior when close zoom root #98
  * Improve tests stability #92
  * Migration: drop empty table `new_edges` (crap left after #16)
  
  Refactoring:
  
  * Replace Graph methods with commands #97 (reduce coupling between classes)
  * Extract common interface to the Goals class #68
  * Toggle views independently from each other (inner preparations) #67
  
  Compatibility breaks:
  
  
negative.code: 
  New features:
  
  * Use two link categories: parent-child vs bloker-blocked https://github.com/ahitrin/SiebenApp/issues/16[#16]
  * Use nested zoom levels https://github.com/ahitrin/SiebenApp/issues/17[#17]
  
  Other improvements:
  
  