[Buildroot] adding dhcpcd

[John Stile]

I have a need for an RFC2131 compliant DHCP client, which dhcpcd
advertises to be (specifically  it needs to detect if a dhcp server
becomes available).

I am using buildroot-2011.11.

I tried to add my own package to buildroot, to build dhcpcd, but I have
no idea how to go about integrating into the system.

I configure static vs. dynamic via /etc/network/interfaces, but should I
do next?  

How does the default system decide what to do with networking?
What is the default dhcp client, and why isn't it RFC2131 compliant?