Add fullscreen and presentation support for IE11.

This amazing browser does camelCasing differently
for event names and also does not support the
isFullscreen or msIsFullscreen property on document.

Therefore this commit keeps track of the fullscreen
state with a custom flag, instead of asking the browser
for it.
Hide presentation button when there is no fullscreen api
Merge pull request #472 from adityab/ie-viewer-fullscreen

Viewer: Add fullscreen and presentation support for IE11.