Add support for NumPy ndarray to .from_array()

[hcpchris]

At a high-level, the data point and series .from_array() methods should support NumPy ndarray objects as inputs. The fundamental priority is to use NumPy's vectorization to provide a performance boost to Highcharts for Python's handling of data points.

To do:

• Add .from_ndarray() class method to DataBase.
• Modify .from_array() class methods to call .from_ndarray() when the value passed is (or can easily be represented as) a NumPy ndarray.
• Implement DataPointCollection class, representing a vectorized array of data point values.
• Implement data point-type specific sub-classes of DataPointCollection.
• Modify series .data properties to support DataPointCollection instances.
• Add support for propagating attributes on get and set at the series level.
• Add support for propagating attributes on get and set at the data collection level.