Documentation of --bootnodes is outdated

[ripper234]

--bootnodes is documented here and here and here to use a comma-separated style.

However, in this #3547 it seemed comma-separated bootnodes has gone away and if I'm reading this correctly won't be returning since the issue is closed (the workaround is to use multiple --bootnodes instances).

The documentation should be fixed to represent the different usage.

[karalabe]

That was only a bug. AFAIK comma separated bootnodes do work.

[ripper234]

Correct. I was testing with an old version of geth (1.3.x), this works now in 1.6.1.