Rename Manifest.walk() to Manifest.from_walk() to emphasize that it's a constructor
Add Manifest.walk() as an alternative to iterpaths()
Reimplement iterpaths() in terms of walk()
Add testcases demonstrating flexibility of Manifest.walk()
Add some documentation to iterpaths()
Rename iterpaths() to paths()
Improve documentation and implementation of .merge()
More work to whip .merge() into shape: WIP: recursion control
WIP: Maybe this will come in handy?