Reimplement EPhotoCache to delegate the actual photo fetching to
EPhotoSources. When a photo is requested for a given email address,
all available EPhotoSources are dispatched concurrently and a photo
input stream is selected from the result set.
This also utilizes EDataCapture, which is affixed to the returned
GInputStream to capture and cache photo data for an email address.
New functions:
e_photo_cache_add_photo_source()
e_photo_cache_list_photo_sources()
e_photo_cache_remove_photo_source()
e_photo_cache_add_photo()
Renamed functions:
e_photo_cache_remove() --> e_photo_cache_remove_photo()
3bf02daa08