is the ghc type system expressive enough to build a snap state that contains snaplet handlers?  donno...
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cleanup: client script now uses Adchoracy.Resource
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fix: tested executors-not-contained-in-snaplet-state approach; appears to be viable.
method getPathM for HasContentType class and all (2) instances
allow for Either errors when changing nodes in the DB api / MVar backend
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PUT in default model (including test)
s/modifyMVar/readMVar/g
add setPath method to HasContentType class and instances
add property sheet accessors to HasContentType class and instances
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set path in objects before commit to DB
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add insertSGNode to DB api
simplePOSTExecutor
fix: responseError terminates handler
fix: validate RArray vs. RArrayHole