Provides a utility for retrieving the closest known "human readable" name for a
color specified as a hex string. It does this by using an algorithm ported from
ntc.js ( http://chir.ag/projects/ntc ). 

There are 3 different sets of color definitions to choose from:
  Resene ( http://people.csail.mit.edu/jaffer/Color/resenecolours.txt )
  html4 ( http://www.w3.org/TR/css3-color/#html4 )
  css3 ( http://www.w3.org/TR/css3-color/#svg-color )

css3 is a superset of html4.

The user can also supply their own colorfile to use. It should be comma
separated hex,name pairs, and should include the leading #. Commas are allowed
in names.

Currently two output formats are supported -- json, and raw. 

Usage:

As a command-line utility:

$ namethatcolor aabbcc
{"hex_value": "#B0C4DE", "name": "lightsteelblue"}
$ namethatcolor --color-set resene aabbcc
{"hex_value": "#ADBED1", "name": "Casper"}

#same as above
$ namethatcolor -s resene aabbcc

#specify your own color file
$ namethatcolor -c path/to/color/file aabbcc

As a library:

>>> from namethatcolor import NameThatColor
>>> Namer = NameThatColor()
>>> Namer.name('aabbcc')
Match('#B0C4DE', 'lightsteelblue', False, '#AABBCC')
>>> resene_filename = NameThatColor.color_sets['resene']
>>> resene_colors = NameThatColor.get_color_file(resene_filename)
>>> Namer = NameThatColor(color_file=resene_colors)
>>> Namer.name('aabbcc')
Match('#ADBED1', 'Casper', False, '#AABBCC')
