[hobbit] change test name 'conn' to link

[Henrik Stoerner]

On Mon, Feb 21, 2005 at 12:03:05PM +0100, Marco Avvisano wrote:
> In my bb installation i have renamed the conn test as 'link'.
> 
> I would like to change it also in my hobbit installation
[snip changes]
> Now the column link is generated but no larrd graph.

The "conn" columnname really wasn't configurable - hobbitd_larrd
would always assume it was either "conn", "fping" or "ping".

So I took this as an opportunity to clean it up a bit. The ping
column name is now defined solely via a PINGCOLUMN environment 
variable.

Also, I decided that having to mess with the LARRDS setting just for
network tests was silly. So instead, all of the RRD- and graph-code
will automatically pick up simple network tests from the bb-services
file.


Henrik