detect-cycle-algorithms detect just one cycle

[verbraucher]

The detect-cycle-algorithms detect just one cycle.
It would be great if the algorithms can recognize more cycles than one, in case there are several.

[kimchirichie]

I've been looking for a javascript implementation of finding all simple cycles in an undirected graph and found none. This enhancement would greatly benefit those looking to implement quick solutions to cycle detection.

[DCtheTall]

@trekhleb I'd be interested in attempting a PR for this at the start of this coming week.

[DCtheTall]

Currently blocked by issue #302.