Fix in Dygraph.log for IE8

In IE8, the console.log functions aren't true Javascript functions. They don't support the "apply" or "call" methods.

All Javascript code stopped working when a log message was being generated, therefor this small fix.
Merge pull request #234 from wimme/patch-2

Fix in Dygraph.log for IE8
Add test suite for DygraphOptions object. Fix broken method in it.
Merge pull request #238 from kberg/master

Add test suite for DygraphOptions object. Fix broken method in it.
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
Merge pull request #233 from lucasbergman/master

some small Closure-cleanliness fixes
Merge branch 'master' of github.com:danvk/dygraphs into closure

Conflicts:
	dygraph-options.js
Reponses to code review for https://github.com/danvk/dygraphs/pull/237