Sysctl lense fails for keys that contain colons (":")

[mstud]

We have something like this in our sysctl.conf:

net.ipv4.conf.ib0:0.arp_filter=1

Augeas cannot parse this. There is a related issue for keys containing slashes already (#668), but this here should be much easier to fix, as : is not part of augeas paths, right?
Thanks in advance.

[teclator]

It looks like it also fails parsing a variable containing a wildcard like:

net.ipv4.conf.*.rp_filter = 2

[jengelh]

The lense may need more review still:

» perl -e 'system("ip", "link", "add", sprintf("dummy%03u", $_).chr($_), "type", "dummy") for 0..255'
» sysctl -a | grep -P 'dummy.*unres_qlen_bytes'
net.ipv4.neigh.dummy033_.unres_qlen_bytes = 212992
net.ipv4.neigh.dummy034".unres_qlen_bytes = 212992
...
net.ipv4.neigh.dummy061=.unres_qlen_bytes = 212992
...