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.
#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
Merged from master