fix namespace bug in testing

	modified:   specs/histogram_spec.js
added rectangle
added initial quadtree
added quadtree splitting
added clear to quadtree
added line and point support to contain

Note: line and point require the dataType attribute,
  otherwise contain will assume the dataType is a rectangle.
added insert to quadtree
added line and point support to intersect

* Also modified test to be shared by intersect and contains.

Note: line and point require the dataType attribute,
otherwise intersect will assume the dataType is a rectangle.
added query to quadtree
add default dotplot configuration
dotplot configuration should update defaults.
added extent to the plot
render an empty plot
add title to plot
add default style to the dotplot
rename viewport width and height
added axis labels
add support for multiple coordinate systems
added the viewing rectangle