Import point names into skeleton data.

Names in the name attribute are treated as whitespace separated.
If the left and right point share a name it is imported as it.
If the left point has a name that the right point has not it is prefixes by 'left-'
If the right point has a name that the left point has not it is prefixed by 'right-'

Thus if left has "hello world" and right has "hello univers" the result is
"hello left-world right-univers"
auto-whitespace and some language
repair setting class-names when loading a skeleton PenStrokePoint