Introduced Cruchyroll plugin

chunchyroll: initial implementation of the API object

crunchyroll: removed expiration from the API (to avoid complexity) and finished the plugin

crunchyroll: added options

crunchyroll: added extra check when parsing the given url

crunchyroll: modified behavior to allow un-authenticated access. Premiun-only streams report a NoStreamsError

crunchyroll: rework api creation to use username & password when credentials don't work

crunchyroll: use cache to store auth and session credentials

crunchyroll: remove crunchyroll-credentials cli option

crunchyroll: remove debug prints

crunchyroll: added dateutil to the dependencies of the package

crunchyroll: added documentation

crunchyroll: always reinstantiate the session

crunchyroll: added purge_credentials option to clean the cache from credentials

This is useful when you need to recreate the session for the server to "forget"
the data stored in your previous session.
e.g. when trying to access over a proxy, your old session will contain
information about your region, forbidding you to access to region locked
content even if your proxy is within that region.

crunchyroll: remove dependency to dateutil by means of using a custom parse function

crunchyroll: updated docs

curnchyroll: added some comments to the plugin itself

crunchyroll: authentication isn't obligatory.

crunchyroll: typo when logging a warning

crunchyroll: removed live from the plugin matrix (not tested)

crunchyroll: few typos on cli docs

crunchyroll: fixed option set as playeropt instead of pluginopt

crunchyroll: clarify that username an password are only for accesing restricted content

crunchyroll: added cli options to the docs

crunchyroll: docs formatting

Added myself to AUTHORS

crunchyroll: added stream weight

crunchyroll: ignore adaptive stream