Fixes for encoding.{h,c}: compile on Linux and Mac
Grouped example configs
Print human readable time for rev-Timestamps
Aggregates take flow and packet timestamps

Previously, timeouts for flows have been calculated using
the system clock and not the PCAP or IPFIX timestamps.
This behavior is now changed for both the PacketAggregator
and IpfixAggregator.

fixes #19
fixes #20
Fix exporter ip
Merge branch 'flow-timeout-changes'