Merge packages into a single package.

Many projects need functionality both from core and music_rnn/ music_vae. For example, you may need to use the NoteSequence or ControlSignal libraries as well as the main model class.

Also, some projects may use both RNN and VAE.

Currently this doesnt seem possible as RNN and VAE are in separate bundles, both of which contain their own copy of core as well as Tensorflow.

Would it make sense to create a magenta-full.js bundle to easily include everything?

[adarob]

Our current plan is to move all of our current packages into a single @magenta/music package, leaving room for future models that don’t work with NoteSequences.

@cghawthorne, we should probably restructure the directories, e.g., move music_vae.ts and music_rnn.ts into a models directory. data.ts should probably be renamed to converters.ts since we have other data libs.

[teropa]

This’ll also maker #29 easier, as a Player class (and other demo code) can be shared between RNN and VAE demos without having to package it up into the NPM modules.