Added support for Javascript Date to Julia DateTime

A variable of Javascript type Date is automatically converted to a variable in Julia of type DateTime. The Julia type DateTime is available in Julia version 0.4 and higher. See Datatype Mapping for details.

Added support for Javascript Buffer and Native Arrays

Support for the special array classes provided by node including Buffer, Int8Array, Uint8Array, Int16Array, Uint16Array, Int32Array, Uint32Array, Float32Array, and Float64Array has been added. See Buffer and Native Arrays for details.