Closure fix; force cast from Element to Node.
Closure tweak: variable 'd' declared twice within the same method.
Closurize dygraph-options.js. Not done.

Also fix bug: this.labels_ was never used! Booo...
Closure fix type Dyraph->Dygraph.
Closurize rgbcolor.js
Merge pull request #238 from kberg/master

Add test suite for DygraphOptions object. Fix broken method in it.
Some closurifying dygraph-canvas and dygraph-layout.
dygraph-utils.js: isElementContainedBy -> isNodeContainedBy

This fixes a type nit when using the Closure Compiler, since walking
parentNode can give an Element or Document node, not just an Element.
dygraph-tickers.js: Fix variable redeclaration
dygraph-utils.js: Remove trailing white space
dygraph-utils.js: Make Dygraph.error and Dygraph.update public

These seem like reasonable utility functions, and they were used outside
of Dygraph (specifically in DygraphOptions). Making these non-private
resolves Closure Compiler warnings inside dygraph-options.js.
Make dygraph-options.js warning-free under Closure Compiler
#Bug 333: Support for passing point index to drawPointCallback and drawHighlightPointCallback added
Added idx parameter to option-reference
Code formatting
Added test for passing the correct idx to pointDrawCallback and hightlightPointDrawCallback
Fixed minor issues
Merge pull request #239 from timeu/bugfix_upstream

#Issue 333: Pass point index to drawHighlightPointCallback and drawPointCallback
Bugfix: avoid exception when one series is hidden
Merge pull request #240 from timeu/bugfix_upstream

Bugfix: Avoid exception when returning the index of the point and one or more series are hidden