[COOK-2449] Make the distribute download location an attribute

Add attributes to define the location of the distribute install script and the
package location. This allows independence of external sources that when down,
cause installation of distribute to fail.
Break up distribute_options_download_base attribute

Change the `distribute_options_download_base` attribute to
`['distribute_options']['download_base']`.
Merge pull request #30 from aweber/master

[COOK-2449] Make the distribute download location an attribute