Overhaul and extend palette sub-menu of color selection menu

[jbunke]

Tasks:

• Add buttons:
  • Remove palette button
  • Create new, blank palette button
  • Move selected color left/right in palette buttons (precondition is selected color is in palette)
  • Palette settings (launches dialog akin to layer settings button)
    • Make name editable
    • Immutable palettes cannot be edited (button precondition is mutability)
• Split palette buttons along lines of functionality into two rows - can still be created with calls to icon button populator; offset second row segment position (Coord2D) by 0, Layout.BUTTON_INC
• Extend palette color button so that shift-clicking buttons excludes them from shading and palettization processes
  • Add final Map<Color, Boolean> inclusionMap field to Palette class - propagate changes to colorSequence contents to inclusionMap
  • Add exclusion overlay sprite and render above potential primary/secondary color selection overlay on palette color button
• Assign and implement shortcuts
• Write and check tool tips and info page blurbs