Node to wikitext

[kristian-clausal]

When parsing lists, Wtp.node_to_wikitext will not reverse the transformation correctly:

# line 1
## line 2
#: example 1
#: example 2

becomes:

# line 1
## line 2
#:#: example 1
#: example 2

This seems like the result of a really old kludge that seems unnecessary now. I think WikiNode has changed between now-and-then, and the prefix of the line might have been explicitly added to only later so the old code wasn't update and there was an extra kludge inserting "#"+":" when two lists were next to each other (as in when you have a line starting with "#" followed by ":", for example; same depth, different lists).