Implement support for src_type

[gwilliams]

Blitline implemented a new src_type value on the primary request.

The values of src_type are a little sketchy... however, it looks like the following can be set:

screen_shot_url -- will take a live screenshot of any supplied web page multi_page -- Allows processing of multiple pages of a PDF document. Has optional "pages" (page numbers) array for processing individual pages

Example of screenshot processing:

{
    "application_id":"YOUR_APP_ID",
    "src":"http://www.chargify.com/",
    "src_type":"screen_shot_url",
    "functions":[
        {
            "name":"resize_to_fit",
            "params":{
                "width":800,
                "height":"9999"
            },
            "save":{
                "image_identifier":"external_sample_1"
            }
        }
    ]
}

For examples of json required for multi_page support, see http://www.blitline.com/docs/pdf

[tednyberg]

This would be great, especially to be able to use "burst_pdf" to convert PDF documents that are larger than 20 pages.