Updated API

Add support for step factors

Important fix to calculateAdvance - don't advance both if row is just one short, as this can happen spuriously

I think this will have to do

Types were not quite correct - confusion between mono and poly vectors. Could usefully improve this. Add a full-size file-backed Real variant (which is what exposed this)

Merge from branch filebacked

Switch entire state when complete, so that all working data can be garbage-collected; add tempDir

Use "live" vectors when still calculating forward face; store thereafter. Much faster

Handle deleting costContainer properly

Concrete file-backed versions

Sketch out use of a file-backed vector

Make it possible to construct constrained DTWs with on-demand feature vectors

Add silence threshold; print costs from constrained-only runs too

Include cost output from "both" mode as well

Colour images, and a bit more info output & alignment tweaking

Further cost reporting; normalise in example

Add function to retrieve total cost

Report stats

Simplify, & restore image saving with MLton compatibility

Backed out changeset 67a761f7d2b1. Turns out there is nothing to gain at all, because we need the lengths of both feature vectors at the outset - even the constrained DTW isn't (yet?) written in a way that avoids this - and we don't know those without completely filling both