Add low power profile auto-setting if, on opening mpv, the battery mode
is detected. This will not automatically change when laptop is beginning
to charge/discharge *during* mpv being open.
Sending links to mpv limits the quality to 1080p, to be able to stream
it with my connection, and since I can not display more.
Fixed mpv taking ages to open for ytdl streams. (or anything else which
takes a while to load)
Mpv had to wait until it had enough buffer to begin playing and only
then would open its main window. With this fix it immediately opens the
window, and starts playing whenever it is ready.
