Convenience class for obtaining styling information for elements.
Add more documentation to StyleCache.
Remove check because element is always defined.
Fix the function description for parsing a positive number or percentage.
Remove console from jsline keywords.
Clarify class names and improve documentation.
Class names should be added to the style chain after the style name.
Bring documentation about style chain keys in line with practice.
Clearer variable names.
Also add master page to the list of parsed master pages after parsing it.
Merge pull request #473 from vandenoever/styleclass2

alternative convenience class for dealing with ODF styling information
Move isEmpty and isODFNode from OpRemoveText.js to OdfUtils.
Rename OdfUtils.isEmpty to OdfUtils.hasNoODFContent,
which is much more precise.
Additionally, it should return true on textNodes only if
they are children of ODF elements.
Add property mergedParagraphStyleName to OpRemoveText spec.

* Make TextController specify the mergedParagraphStyleName
when generating a RemoveText operation. No longer let
OpRemoveText decide the merge order from the context.

* Remove the text:style-name attribute on a paragraph
if the aforementioned property is an empty string.

* Add tests for this.