Basic auth

Cherry picking basic authentication from https://github.com/InnovaCo/websocket-php/commit/e553db42889c64f08ae700bb202ef706d0ddfad8#diff-d25a5d86da2d487fe7787e90709a5ecbR91

Adding test for basic auth.

Increase of echoserver timeout helps those trying the example manually :)

Btw, chromium doesn't send any Authorization header for basic auth…
Add a comment saying what unit it is. That's likely the reason for the bad choice of the old value.