* edit/edcore: Implement some insert-mode functions for word-based movement.
Implemented `kill-word-right`, `kill-small-word-right`, `move-dot-left-small-word`, and `move-dot-right-small-word`.
* eval/bundled: Create default bindings for `kill-word-left` and `kill-word-right`.
* edit/edcore: Fix a dumb arithmetic error in `kill-word-right`.
* edit/edcore: Purify move- and kill- buffer commands.
* Implement category-based movement, per discussions in #696
* edit/edcore: Design unit tests for moveDot functions.
* edit/edcore: Revise categorizer-based movement for clarity; rewrite some comments.
Following the examples of 'kill-small-word-left' and the 'move-dot-*-word'
functions, I added two new functions to move the cursor left or right,
stopping at the next "small word".
This would typically be used for Ctrl+Left & Right, e.g.:
edit:insert:binding[Ctrl+Left]=$edit:move-dot-left-small-word~
edit:insert:binding[Ctrl+Right]=$edit:move-dot-right-small-word~
* Add compatibility test with old implementation
* Add color type
* Add basic style structs and utilities
* Add structs for styled segments and texts
* Add default style transformers to reimplement $edit:styled~
* Add builtins to manipulate styled segments and texts
* Rename style 'underline' -> 'underlined'
* Fix test case
* Add conversion from styled text to ansi sequences
* Return errors rather than throwing
* Validate the type of boolean options
* Delegate old to new styled function
* Rebase for new test framework api and expand test cases
* Remove old builtin function $edit:styled~
* Use strings to represent colors
* Convert bool pointers to simple bool values
* Validate color strings
* Do no longer expose builtin style transformers
* Fix confusion about pointers
* Make outputs more stable
* Expand tests
* Use pointers instead of passing setter functions
* Unexport and rename color check
* Use the empty string for default colors
* Expand tests
* Simplify styled transformers
Now there are three transformers for each boolean style attribute that
allow setting, unsetting and toggling the corresponding attribute.
* Rework and add doc comments
