Added nITG's various column specific & other misc modifiers (#1468)

* Added stealth control, ZBuffer & DizzyHolds mod

Modifiers added:
StealthPastReceptors
DizzyHolds
StealthType
ZBuffer

* Removed theme metrics that are now mods.

Removed metrics:
DrawHiddenNotesAfterReceptor
DizzyHoldHeads

* Implemented nITG's Shrink modifiers

Modifiers Added:
ShrinkLinear
ShrinkMult

* Implemented nITG's Attenuate mods.

Modifiers added:
AttenuateX
AttenuateY
AttenuateZ

* Implemented nITG's pulse modifiers

Modifiers added:
PulseInner
PulseOuter
PulsePeriod
PulseOffset

* Implemented nITG's DrawSize and Bounce modifiers.

Modifiers Added:
Bounce
BouncePeriod
BounceOffset
BounceZ
BounceZPeriod
BounceZOffset
DrawSize
DrawSizeBack

* Added nITG's column specific Dark & Stealth mods

Modifiers added:
Stealth<1-n>
Dark<1-n>

* Finish adding nITG's column specific mods

Modifiers added:
ConfusionXOffset<1-n>
ConfusionYOffset<1-n>
ConfusionzOffset<1-n>
Reverse<1-n>
Tiny<1-n>
Bumpy<1-n>

* Documented new modififers

* Changelog housekeeping

Fixed a typo and added this branch's PR into the changelog.

* Last bit of clean up. (#3)

* Fixed up one line of the changelog

* Add MrThatKid to credits.

Themes/_fallback/Scripts/04 CreditsHelpers.lua

@@ -87,6 +87,7 @@ local stepmania_credits= {
 		{logo= "kyzentun", name= "Kyzentun"}, -- new lua bindings, theme documentation
 		"Mad Matt", -- new lua bindings
 		"Matt McCutchen", -- minor fix for some dance pads on linux
+		"MrThatKid", -- nitg modifiers
 		"NitroX72", -- pump/frame noteskin
 		"nixtrix", -- various BMS features and other fixes
 		"Petriform", -- default theme music