feat(color): add Slider & Choice widget option types

[philmoz]

Changes:

• Adds two new types for widget options - SLIDER and CHOICE.
• Fix ALIGNMENT widget option type.
• Add missing Lua constants for fonts and widget option types.
• Cleanup up widget code.

New Lua contants:

• STDSIZE - default FONT (STD size)
• STDBOLD - bold FONT (STD size)
• INTVAL - Number edit widget option type
• SRCVAL - Source select widget option type
• SLIDER - Slider widget option type
• CHOICE - Choice popup widget option type

Slider widget option:

  { "Slider", SLIDER, 0, 0, 19 }

Parameters are name, type, default value, min value and max value.
Option value is a number between min & max,

Choice widget option:

  { "Choice", CHOICE, 1, {"LiPo", "Li-Ion", "NiMH"} }

Parameters are name, type, default value, and table of choice names.
Option value is a number from 1 - number of entries in the table of names.

[pfeerick]

New option types are looking handy... Think Offer will like those for his widgets ;)

The only "problem" I see with the slider, which could be be said for other places in the UI, but probably less of an issue there, is if for instance you want to use it for say cell count, you don't know the specific value selected... not sure how to resolve that... other than perhaps being able to draw it on the slider itself for a duration after changing it?