(svn.tour.treeconflicts): Move material related to 1.5
into a side-bar. Also, we don't "force" users to resolve
conflicts, so phrase it as "giving the opportunity"
instead. Also, add a footnote explaining that files
with textual conflicts can of course be committed with
their conflict markers intact, so when we say Subversion
was "forcing" users to resolve text conflicts, this has
to be taken with a grain of salt.
Suggested by: julianfoad
(footnote added by myself)
