update readme
contributor shortcode defaults to `donations="yes"`
refactor: use templates for downloads-shortcode
refactor: contributor.avatar is an object now
templates: add *.license as alias for *.license.html
turn episode.duration into an object
remove template object aliases
render avatar images via template
remove aggregate accessors from duration object
add Twig filter: padLeft
episode-list.twig: fix episode.duration display
Changes to Services

* Added 500px, Last.fm, OpenStreetMap and Soup
* Services List is now in alphabetical order
* Added PSN Icon
fix [podlove-podcast-contributor-list]

	now only contributors set up in podcast settings are shown
render licenses via template
add documentation
update readme
more doc updates
adjust default templates
handle incomplete licenses in template
Merge pull request #337 from podlove/social_media_account_pack1.1

Changes to Services