Added positionMergeWithNeighbours, and use this to merge the nodes surrounding the selection start and end elements, rather than mergeWithNeighbours (which we weren't using correctly anyway).
Added positionMergeWithNeighbours, and use this to merge the nodes surrounding the
selection start and end elements, rather than mergeWithNeighbours (which we weren't using
correctly anyway).

corinthia/corinthia-editorlib,corinthia/corinthia-editorlib,corinthia/corinthia-editor,corinthia/corinthia-editor,corinthia/corinthia-editor,corinthia/corinthia-editorlib,corinthia/corinthia-editorlib,corinthia/corinthia-editorlib,corinthia/corinthia-editor,corinthia/corinthia-editor