Moved creation of arlSpellTooltip from addon:InitializeFrame() into the main file body, and changed its parent from MainPanel to UIParent.

Moved creation of arlSpellTooltip from addon:InitializeFrame() into the main file body, and changed its parent from MainPanel to UIParent.
In SetSpellTooltip(): Copy GameTooltip's main settings over to arlSpellTooltip so AddOns which modify GameTooltip will work on it.
Moved the setting of arlSpellTooltip's scale from addon:DisplayFrame() to SetSpellTooltip(), where the config option will actually work.
Moved the setting of arlTooltip's scale to after its anchor points have been cleared then set so the config option will actually work.
Moved TipTac skinning of arlSpellTooltip from addon:InitializeFrame() to SetSpellTooltip().
In giveDisplay(): Change L["UI Scale"] to _G.UI_SCALE, removed check for addon.Frame's existence, and removed the attempt to set the scale of arlTooltip and arlSpellTooltip.
Removed "UI Scale" from the localization table.
Removed some comments for which their code was obvious in function.
Removed global references to arlTooltip and arlSpellTooltip.
Added file-local arlTooltip, as there is no reason for it to be global.