Updates send_string functionality, adds terminal feature (qmk#1657)

* implement basic terminal stuff

* modify send_string to read normal strings too

* add files bc yeah. working pgm detected

* pgm detection apparently not working

* adds send string keycodes, additional keycode support in send string

* implement arguments

* [terminal] add help command

* [terminal] adds keycode and keymap functions

* [terminal] adds nop.h, documentation

* update macro docs

fix for toggle tap dance

update some keymaps that broke w/defaults

Merge branch 'master' of https://github.com/qmk/qmk_firmware

Improve and simplify RGB Knight mode (qmk#1677)

* Simplify RGB Knight mode code, and make it look closer to KITT

* Remove RGBLIGHT_EFFECT_DUALKNIGHT_LENGTH

Fix Kitt and its default behavior (qmk#1674)

Alterations and documentation updates for j3rn Ergodox EZ keymap (qmk…

…#1656)

* Add second set of AltSft and Alt

* Insert the play key between previous and next

* Update documentation

add UC_OSX_RALT to make unicode use the Right Alt key on OSX

Update drashna's keymap (qmk#1649)

* initial commit for my custom layout

* fix switching into and out of numfun layer

* enable tap dance to lock layers

* enable layer indicator LEDs

* remove Colemak2 layer because it was dumb

* remove handler for nonexistent keycode

* add new movement keys to lower layer

* standardize indentation because I'm not a monster

* add Woodpad keyboard with Michael's Tryggve layout

* Add dvorak/colemak layers

* add hash

* Update keymap.c

* Fixed OSL Symbol layer layout issue

* Minor later tweak

* Clean up actions

* Diablo 3 macro keys remove

* Fixed numbad issues

* Remove Underglow toggle

* Fix layer consistency

* cleanup of code

* line feed

* small fixes

* Major merge

* Merge cleanup on my keymap

* Cleanup

* Update compile command

* Swapped arrows

* Additional cleanup

* Revert "Woodpad"

* update

* minor update

* staging for pull request

* Finish removing layer underglow toggles

add a `git-submodule` make target.