* Import lists and variables from SB2
* Switch to Variable and List objects
* Add Clone.lookupOrCreateVariable, Clone.getVariable, Clone.setVariable
* Add (get, set, change) variable blocks.
* Copy variables and lists on clone instantiation
* Move variable options closer to blocks
* Add list primitives
* Move variable and lists storage to `Target` instead of `Clone`
* Move _computeIndex to a Cast function
* Rename `getList` -> `getListAsString`
* Renames renames
* Remove extra check in Cast.isNaN
* Fill out color utilities
* Amend Color.decimalToHex name
* Add `Cast.toScaledRgbColor`
* Add touching color, color touching color blocks
* Fix scale of Cast.toRgbColor
* Fix format of colors to use renderer-style lists
* Update `Color.decimalToRgb`
* Lint self
* Fix SB2 variable imports!
* Fix expectedArg field types
* motion_pointindirection uses math_angle
* Fix "think for secs" expected input
* Add handling for empty input case (empty if-else, for example)
* Fix opcodes for if_else, repeat_until, set tempo
* Specialized number fields for SB2 import
* Convert color picker numbers to hex in SB2 import
* KEY_OPTIONS -> KEY_OPTION
* Backdrop blocks get BACKDROP
* Update toolbox XML to match naming changes
* Merge in math_angle case
* Move color converter to its own utility
* Fix merge conflicts
* Add negative color check.
* Fix keyoptions naming
* Pen JSON tweak post-scratch-blocks update
