remove code duplication in event binding
remove more code duplication for default open in sections by extracting common code in a separate method
remove code duplication: refactor condition for default opening of sections
remove accidental global variables
extract cookie retrieval code in its own method to remove code duplication
toggler should be separate from collapsible element
retrieve "id" attribute for collapsible element via a central function which traverses all parents if necessary to find the id attribute
last element in cookie was never deleted because of bad check for 'falsish'
Merge pull request #1 from FelixSchwarz/master

Merge