Provide character style properties for controlling automatic merging of adjacent runs

[drmacro]

There are cases, such as setting the language on a character style, that results in a sequence of runs with the same style when the author action was to style a single multi-word phrase. In this case the default behavior is to produce distinct result elements, one for each run.

Need to make it possible to merge adjacent runs with the style e.g., an attribute like "mergeAdjacent=true|false with a default of "false" on characterStyle.

[drmacro]

The motivation for this comes from the way Word handles runs of text in non-default languages. From a private discussion:

Looking into the small test polish units DOCX more closely, it looks like Word is making a separate run for each word and each blank in order to add spell checking directives around each word. That results in a sequence of runs, each with the applied style. Thus they come out as multiple inline elements for the reason I explained before.

This suggests the need for a "merge adjacent runs" control on character style mappings so you can handle this case.

Lacking this feature, the final-fixup mode could be used to add custom processing to do the merging.

There may be a way in Word to turn off the spell checking so this doesn't happen but I don't know enough about the spell checking features in Word to know what that might be.