* encoding: support different encoding for files, make utf8 implementation
  more robust

* support multi column chars

* right-to-left, bidirectional text

* key binding support

* Mouse support

* Crash recovery support (swap files)

* Sanitize prompt history handling, hooks should not have side effects
  on history

* automatic line splitting/paragraph formatting

* Use boost::filesystem for path handling

* folding support

* spelling support

* improve info boxes, how to make them hide

* removable, groupable hooks

* more than 16 colors support

* investigate 'kakdiff'