Refactored iframe loader to directly load content
#142 more refactoring
merge
Removed mathjax timeout because it was too short and it breaks pagination if we render pages before it is done loading.
Merge commit 'c14d3752d6154ca9d3c23ab092c8d2f0e3408aff' into txtr_dev

automaticPageTurnEnabled -> mediaOverlaysAutomaticPageTurn

* commit 'c14d3752d6154ca9d3c23ab092c8d2f0e3408aff':
  Removed mathjax timeout because it was too short and it breaks pagination if we render pages before it is done loading.
  #142 more refactoring
  Refactored iframe loader to directly load content