turn core.Async from class to namespace
use core.Async.destroyAll for Editor.destroy
Merge pull request #469 from kossebau/makeCoreAsyncANamespace

Make core.Async a namespace
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.
Add test for frame position.
Add a helper function to get the bounding rectangle for an ODF page.
Improve positioning of frame that relative to page.
Add type that is a union of ClientRect and a struct with the same members.
This makes is possible to use them interchangeably.
In older browsers, positioning is only allowed on whole pixels.
The positioning test should set the allowed error higher in such browsers.
Add more supported length units.
And add a bit of documentation.
Check for null return value for getBoundingClientRect.
Slight clarification of exception.
Add tests with draw:frame directly in office:text.
This requires position: relative in office|text to get the frame positioned properly.
Simplify layout tests by having common styles.
Fix positioning for horizontal-pos="left" and vertical-pos="top".
Code cleanup and add a test for anchor="as-char".
Move getStyleElement from odf.Formatting to odf.StyleInfo.
Also add description to some functions and make convertToPx clearer.
Fix positioning of frames in ODP files.
This fixes a regression. In ODP, the location of frames is relative to the top and left of the page, but this is not explicitly specified in the styles.
Remove type odf.OdfRect.
It is not needed any more. No call to getPageRect modifies the resulting ClientRect.