Remove plugins using dead services.
Add a HTTP session to the plugin API.

This HTTP session is shared between all
plugins loaded in the Livestreamer session.
setup.py: Don't import version from package.

Since we now import a requests session into
the session module we can't import the livestreamer
package in setup.py anymore.
stream.akamaihd: Update to use new HTTP APIs.
stream.hds: Update to use new HTTP APIs.
stream.hls: Update to use new HTTP APIs.
stream.http: Update to use new HTTP APIs.
plugins.afreecatv: Update to use new HTTP APIs.
plugins.alieztv: Update to use new HTTP APIs.
plugins.azubutv: Update to use new HTTP APIs.
plugins.bambuser: Update to use new HTTP APIs.
plugins.cast3d: Update to use new HTTP APIs.
plugins.crunchyroll: Update to use new HTTP APIs.
plugins.cybergame: Update to use new HTTP APIs.
plugins.dailymotion: Update to use new HTTP APIs.
plugins.dmcloud_embed: Update to use new HTTP APIs.
plugins.dmcloud: Update to use new HTTP APIs.
plugins.euronews: Update to use new HTTP APIs.
plugins.filmon: Update to use new HTTP APIs.
plugins.filmon_us: Update to use new HTTP APIs.