alpha not treated correctly as a data spec

[bryevdv]

The following code should produce patches with a range of alphas, but does not.

from bokeh.sampledata import us_counties, unemployment
from bokeh.plotting import *
from numpy import linspace

county_xs=[
    us_counties.data[code]['lons'] for code in us_counties.data
    if us_counties.data[code]['state'] == 'tx'
]
county_ys=[
    us_counties.data[code]['lats'] for code in us_counties.data
    if us_counties.data[code]['state'] == 'tx'
]

county_alphas = linspace(0, 1.0, len(county_xs))

output_file("test.html")

patches(county_xs, county_ys, fill_color="black", fill_alpha=list(county_alphas),
    line_color="white", line_width=0.5, title="Texas Unemployment 2009")

show()

[bryevdv]

This is now fixed, see attached screenshot