app projects to app folder
FileSystemDataStore handles a directory

Extended tests
FileSystemDataStore handles handles root directory (currently
information about directory leaks)
Contains ...
large scale trim and restructure

metric agent no longer functional
readers and writers dropped
rationalised interfaces to single-spec snapshot provider, consumer
direct configuration

pass configuration elements to sources to configure at instantiation
first cut for coordination (chains)

creation of Chain class to tie together source and multiple sinks
idea is to have main chains that tie a source to a circular buffer and a
store
then have secondary chains that draw from the circular buffers to
plotters