Update documentation for AxisGridlines

Adds docs for lineColor and lineWidth, and updated docs for allGridlines
Removed comments for drawGridlines, so docs are not generated.
Fixes up Axis documentation

Removes documentation from private methods, and adds it to some public
methods which were missing it.

Also renames series.accessor as "valueFunction", and adds a findMin
method to the axis. Removes the vertical() method from the axis, as this
was just !horizontal().
Fix up documentation for the Series

Adds docs for keyFunction, valueFunction, findMin and findMax, and makes
sure all methods use the @memberof documentation specifier
Fix up BubbleSeries docs

Removed findMax and xFunction/yFunction, as these are already handled in
the parent Series.

Adds docs to radiusFunction.
Fix up ColumnSeries docs

Removes tooltipFunction, as this is done by the parent Series.
Fixes up docs for stacked and findMax
Update LineSeries docs

Adds docs for LineSeries.showPoints
Update MarkerSeries docs

Adds docs for MarkerSeries.widthFactor
Update Row series docs

Removed tooltipFunction, as this is handled by the super Series. Ditto
for this.keys.
Updates tooltip docs

Public documentation for tooltip now includes styles, offset, and show/hide
Update table docs

Removes some docs from private methods, and improves the docs for top,
columns, ascending and descending.
Fix axis-adding issue

Noticed that the axes() methods do not wipe out the current axes before
adding new ones. This meant that adding an axis twice would mean it
appeared twice in the axes arrays.
Add docs to chart