Convert the build to multiproject-style

Don't want to add (samza, storm, spark, akka, etc.) deps to the main
project, so this should be useful soon.
Update SBT
Cancel on ctrl-c
Graph -> Flow, Map -> Seq

I've been calling it this in my head, and I think the intuition's
better, so I'm going to go with it.

Also, I'm now preserving ordering -- because I can, and because it's
helpful to have a topological sort in some cases.
Rename some fields in Flow
Add new Twitter 'reach' example

Wow -- this comes out quite nicely.
Add file with high-level description

Terrible, terrible prose... but it's somewhere to start.
Pull in some notes from the coast-mini branch
More notes
Add standard test deps to all projects
Split transform into aggregate and pure versions

I'd like to compile the pure version differently, so it's useful to
reflect the distinction in the AST.
Publishing info

Add organization to the build, and publish to the local maven repo. This
should make the code visible to both SBT and Maven projects.
Add Samza project

Not sure what this is going to look like yet, but charging ahead.
Hide visibility of common utilities

I don't really want these to leak into client code.
Sketching out a Samza integration

New plan: Samza gets deployed as a) a tar with a bunch of jars /
scripts, and b) a config file. The user's compiled code should be able
to take the graph and generate a bunch of configs, which include
serialized functions to run -- individual jobs can then be launched with
both the tar and the config files.
Hacking around with Samza
more notes
add dependency on samza-kv
Stubbing out the Samza integration

Coming along... most of the integration should be hacked out, except for
the packaging and other fun stuff.
Simplify Stream/Builder implementation

Just a few named implementations now instead of a bunch of anonymous
ones.