redo Initial commit

Altered:
- ping, response changed to "Pong!"
- removeByName, changed so that no parameters does not remove songs.
Instead parameter must be "allSongs"
- renameBroadcast, changed "{GS Bot}" to "[EGSA Bot]" to customize for
my broadcast.
- sendMsg, removed "[Bot]:" from all responses. We know this is a bot.
- peek/previewSongs, removed album name, added artist name. GS album
data is often wrong.

Added:
- getPlaylist, inspired Ramouch0
(https://github.com/UlysseM/GSBOT/issues/8), able to add any playlist as
long as you have the ID. (The ID is visible as the number at the end of
the playlist URL)
- rules, copied from davpat's fork (https://github.com/davpat/GSBOT),
but modified to prevent flooding,
- fetchLast, copied from Flumble's post
(https://github.com/UlysseM/GSBOT/issues/1), fetchByName is nice but
sometimes you just want to grab the last songs added