Read only netactivity counter

Use OLPC custom chain in order to focus exclusively
network tcp traffic.

Signed-off-by: Martin Abente Lahaye <tch@sugarlabs.org>
Explicit dependency on powerd

This monitor uses an iptables CHAIN created by powerd,
called netactivity. Iptables counters are reset during
powerd initialization.

Signed-off-by: Martin Abente Lahaye <tch@sugarlabs.org>
Generalize finding method

Mimic the find method format from the datastore, which is
compatiable with how harvest-client current query data for
the reports.

Signed-off-by: Martin Abente Lahaye <tch@sugarlabs.org>
Release 0.1.5-1

Signed-off-by: Martin Abente Lahaye <tch@sugarlabs.org>