Bug 885545 - Create Blobs for Contact photos in the VCF importer

This patch adds support for parsing vCard format photos in its standard base64 and URL forms. Besides the parsing process itself, the main change is that the vCard processing becomes callback based because of the potential asynchronous nature of retrieving photos from URLs.

Most of the line changes comes from moving vcard text from the JavaScript text file to independent `*.vcf` files.

This patch also addresses some minor bugs found along the way.