Require dependencies from the window object

- This way, when a standalone bundle is created, dependencies won't get
  packaged into it (which will increase file size and might be redundant
  if dependencies already present in client app)
- Make Bows an optional dependency
Create main entry point index.js

Used to require directly, and create browserify standalone bundle
Clean dependencies declaration

- Library's direct dependencies go in bower.json as much as possible
- npm's package.json can be used for testing dependencies
- Example's dependencies moved to "devDependency"
Change example to use main entry point

Also:
- Require bows from window object
- Import tideline.less in example.less
Tweak dependencies to make node tests pass

Tests are run in Node so the `window` object is not available. Make sure
it is before trying to use it, and for underscore fallback to Node's
underscore to allow tests to run normally.
Add Makefile and README instructions
Add configurable images base url

Remove hard-coded '../img' path and instead add a configurable
`imagesBaseUrl` attribute to the `container` object that allows apps
using Tideline to tell it where to find the contents of its `img/`
assets.

The `imagesBaseUrl` value is passed from parent to child:
- The `container` passes it to `pool` and `tooltip`
- The `pool` passes it to different `plot` functions
Add Duration.js as a Bower dependency

- Add to bower.json
- Remove from package.json
- Use `js/lib/duration.js` "importer" like other dependencies (checks
  for window object)
- Add note in README
Merge branch 'master' into app-integration

Conflicts:
	example/example.js
Merge pull request #4 from tidepool-org/app-integration

Allow easier integration into a web app