Clarify lifecycle event selection process

Previously, the name "selection" described both a D3.js selection *and*
a function that returned a D3.js selection. This organization reflects
the distinction more clearly. (It also avoids the overhead of creating a
new function via `Function#bind`.)

Add comments to more explicitly explain the intent of the code.
Document `transform` option for Chart constructor

As part of the release for d3.chart version 0.2, the Chart constructor
was modify to special-case an optional `transform` option, copying it
onto the new chart instance [1]. Document this behavior in the
description of the Chart constructor.

[1] Commit fbb389de0b2c5722faa46ae6b2041bb62b57e7d9
Merge branch 'clarify-layer-selection' of github.com:jugglinmike/d3.chart into jugglinmike-clarify-layer-selection
Merge branch 'jugglinmike-clarify-layer-selection'
Merge branch 'build-structure' of github.com:jugglinmike/d3.chart into jugglinmike-build-structure
Merge branch 'jugglinmike-build-structure'
Merge pull request #90 from jugglinmike/document-transform-options

Document `transform` option for Chart constructor
Improve JSDoc usage

Change tag usage to more accurately describe the API, and include
external examples from the Miso project website.