Export enhancements

Placeholder for notes on Export Enhancements.

Extend the Extension:Collection to provide an API
Basic Use Case: Be able to use the collection extension from the cmd line.

Interface (list of function from Collection.php)

 * CollectionAddArticle
 * CollectionRemoveArticle
 * CollectionAddCategory
 * CollectionAddChapter
 * CollectionRenameChapter
 * CollectionSetTitles
 * CollectionSetSorting
 * CollectionClear
 * CollectionSuggestAction (ban, add, remove, undo)
 * CollectionGetBookCreatorBoxContent
 * CollectionGetItemList
 * GetMWServeStatus

irrelevant functions (i.e. interactive mode only):
 * CollectionGetPopupData

Provide parsed & semantically annotated XML of article text (dumps & API)
Use case: Make it easier to reuse the data. This was the #1 recommendation of the Wikimedia Strategy Offline Task Force.

How to get there

 * Build a list of missing semantic information in the current XHTML output
 * Subclass the parser and add
 * semantic information where it is currently missing
 * offer control over how templates are expanded
 * add the new functionality to the API