Unbreak master page rendering in ODPs.

Restricted the `z-index: 1` hack for draw|frame to
frames within office|text, since it was intended for
ODTs in the first place.
Merge pull request #531 from adityab/zframe

Unbreak master page rendering in ODPs.
Make html files of editor and viewer HTML5 validated

Check done with http://validator.w3.org/check
Merge pull request #528 from kossebau/validatedHTML

Make html files of editor and viewer HTML5 validated
Add section "Creating webodf.js" to README.md
Do not duplicate the README in the error messages
Merge pull request #530 from kossebau/buildInstructions

More build instructions
Add dutch translation.
Remove a duplicate entry from the german translation and add some new translation strings in dutch and german.
Merge pull request #537 from vandenoever/nl

Add dutch translation.
Use Error objects in callback passed to "destroy" methods

The currently plain undefined objects are not useful at all, because
the properties are undefined.
Merge pull request #534 from kossebau/useErrorTypeInDestroyCallback

Use Error objects in callback passed to "destroy" methods
The editor's body css should not affect the
office:body element.
Merge pull request #539 from adityab/bodystyle-editor

The editor's body css should not affect the office:body element.
make Webodf version a global property on the new namespace webodf
Merge pull request #535 from kossebau/makeWebODFVersionGlobalProperty

make Webodf version a global property on the new namespace webodf
Add operation test showing issue with split paragraph near spaces
Ensure upgrade whitespace logic always upgrades current and next step

Using step iterators ensures the current and next step are always
upgraded, even if the next step is more than 2 positions away from the
current step.

Additionally, the logic has been corrected to upgrade the character to
the LEFT of the step rather than the right. This better matches the
intended step position as described in README_cursorpositions.txt.

Fixes issues #514.
Add operations test showing empty spans created on paragraph split