issue #41: clean up localization

[bloerwald]

As requested in #41, all localisation usage is now using "non readable" keys with sane prefixes. Since this requires reimporting all localisation data, this also removes unused strings and cleans up some obvious bogus data.

This PR can be reviewed entirely in the data added to the repository. If this data looks sane, it is required to

• delete all localisation data from curseforge
• reimport the data from Localization/rename/*.lua
• delete Localization/rename/*
• remove the ns.L["new"] = ns.L['old'] lines from Core/Addon.lua
• merge

You can test it by replacing Localization/enUS.lua with Localisation/rename/enUS.lua, adding

local L = LibStub('AceLocale-3.0'):NewLocale('PetBattleScripts', 'enUS')
if not L then return end

on top.

[bloerwald]

force push: drop #34, add changelog entry

[bloerwald]

• delete all localisation data from curseforge
• reimport the data from Localization/rename/*.lua
• delete Localization/rename/* d3444f3
• remove the ns.L["new"] = ns.L['old'] lines from Core/Addon.lua