Net component changelog:

2011-11-07 Jose Pedro Oliveira

 * Dynamically detects the network interfaces
   (i.e. the ones listed in /proc/net/dev)

 * No longer needs to fork/exec the external ifconfig command and
   parse its output.  It now reads the Linux kernel network statistics
   directly from /proc/net/dev.

 * Each network interface now has 16 events instead of 13
   (all counters in /proc/net/dev).

 * Adds support for PAPI_event_name_to_code()

 * Adds a couple of small tests/examples

