* drop --auto: When two files have the same content, and a preferred content
expression matches one but not the other, do not drop the content.
+ * sync --content, assistant: When two unlocked files have the same
+ content, and a preferred content expression matches one but not the
+ other, do not drop the content. (This was already the case for locked
+ files.)
* sync --content, assistant: Fix an edge case where a file that is not
preferred content did not get dropped.
* filter-branch: New command, useful to produce a filtered version of the