Now that Compact Language Links also started to add to this list, ULS would
show incorrect language change tooltip notifications. ULS interface language
selection will still keep updating the list of previously selected languages.
Refactored the code a bit: 1) created minimal Store that wraps around plain
localStorage, since mediawiki.storage cannot be used yet. 2) Inlined the
userHasChangedLanguage function to new initTooltip function. 3) Split parts
of the huge initInterface to new initTooltip and initIme functions for
increased readability. 4) Solved a TODO for moving language change recording
out of the tooltip showing code.
Change-Id: If8478a59168d89264f4d46938ac865c0c9a04f25
e3c2950c04