first draft of fft block
added fft block to library
addressed JM's various concerns with my code
removed unecessary double type assertion
Merge branch 'master' of github.com:nytlabs/streamtools into hwio
Merge pull request #383 from mikedewar/hwio

Hwio
build constraint for arm-only on both digital pin blocks (hwio)
Merge pull request #384 from jacqui/master

build constraint for arm-only on both digital pin blocks (hwio)
The ARM library was missing digital pin blocks, and the regular library had a reference to one
Merge branch 'master' of github.com:nytlabs/streamtools
Merge pull request #385 from jacqui/master

digital pin in its right place
merging
histogram counts are floats
Merge pull request #393 from mikedewar/histogram

histogram counts are floats
Merge pull request #381 from mikedewar/kl

KullbackLeibler Divergence
added basic toemail block
using paths for email attrs
doc cleanup
inital fromEmail commit
fromEmail now provides json output