Numark NS6II Controller Mapping

[Swiftb0y]

It is mostly completed / ready for review.
However, I wasn't able to test it yet to the required extend.
Features:

• Full control over integrated lcd display
• ComponentsJS EffectUnits
• Colored Hotcue Pads (already built on the changes from Better support for hotcue colors on controllers #2031)

Known Issues:

• init function missing serato get status sysex msg
• Time displayed on display dependent on duration*playposition (instead of rate-adjusted time_elapsed/time_remaining) (won't fix; I'll consider it while reworking the mapping with QJSEngine)
• NS6II and Mixxx have different crossfader curves (same issue with serato so this might be tolerable)
• slider_pitch soft takeover leds flicker when the slider is moved quickly (L658; requires more complicated solution which I haven't found yet)
• shutdown code still missing
• documentation missing
• cont_pad_mode_selector Led pad index weirdness when two buttons are pressed twice
• Development notes and jshint config still present.
• print debugging statements still present.

Related/Dependent PRs:

• Default HotCueColor integration into ComponentsJS #2220 (components js Default cue color #2153 integration)
• Default cue color #2153 (fallback hotcuecue color)
• Components JS HotcueColor integration #2030 (components js hotcuecolor integration)
• Better support for hotcue colors on controllers #2031 (better hotcuecolor support for controllers)
• Force components.SamplerButton volume to max when not velocity sensitive #2043 (fix for velocity sensitive samperbuttons)
• Fix hotcue_X_color_id ControlObject not set when loading the first track of the Deck #2048 (fix for hotcue color ids controlObjects not set on first track load)
• Make controller shutdown easier for components JS based mappings. #2052 (basic shutdown mechanic for componentsJS objects)
• [DONE] Add indication whether controller callback was successfully disconnected #2054 (check if callback connections are still valid)

[Holzhaus]

What's the status of this PR?

[Swiftb0y]

Stalled. I decided I will rewrite it after #1795 got merged (and we possibly adapted the components library to ES7 as well).
I guess it makes sense to close the PR for now.