xtonhasvim cleanup (#2947)

* FORK!

* WIP - just how i like it

* empty

* more movement

* mouse keys

* more vimminess

* append/insert shift

* WIP - vim macros

* blocked out layer below in cmd mode.

also, about to restart my cmd approach.

* WIP - new vim layer

ripoff of the ergodox one, but rewritten as a state machine.

* debugged some, got key repeat working

* moooar coverage

* moooar coverage

* regular vis mode

* basically done with basics.

* some refactoring

- common movement sequences into helper function
- added some rgb controls

* modkey passthru feature

* stdized on cmd-left/right instead of ctrl-a/e

sadly. as there's no reliable shift-ctrl-e

* indicator lights

* moved vim layer into userspace

* cleaned up some yanking edge cases

* docs and some tweaks to layerescapes

* updated/added license strings

* updated comments

* moved config changes to keymap

* spurious changes removed

* cleanup pass, HT drashna for suggestions

- used _keymap() pattern to better modularize event processing in userspace
- made some static things static
- removed unused function
- improved reset.

keyboards/niu_mini/keymaps/xtonhasvim/keymap.c

@@ -152,16 +152,6 @@ const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
 
 };
 
-bool process_record_user(uint16_t keycode, keyrecord_t *record) {
-  if(process_record_xtonhasvim(keycode, record)) {
-    // do nothing so far
-    return true;
-  } else {
-    // already handled by vim
-    return false;
-  }
-}
-
 /** Set just 4 LEDs closest to the user. Slightly less annoying to bystanders.*/
 void rgbflag(uint8_t r, uint8_t g, uint8_t b) {
   for(int i = 0; i < RGBLED_NUM; i++){