Check in current code of RF24Ethernet

- Moving to new structure similar to the standard Arduino Ethernet
library (Also using UIPEthernet as a reference)
- Currently the library only directly supports incoming connections as a
server, with little to no control beyond receiving data from the
connection
- Can now be used on multiple nodes, but the network address is
hard-coded
- RF24Network support for Arduino receiving fragmented multicast
payloads allows actual ARP protocol handling, and integration with
RF24Network (Using RF24 radio mac addresses at the routing/IP layer)
- Need to add configuration for the MAC address as the radio address,
etc, but wanted to check-in the code
Check-in todays updates

- Library now contains many of the client functions: read, stop, etc for
incoming connections
- Can now set MAC (RF24Network) address from the sketch and
configuration is more like it should be
- Still needs a lot of work
Update readme
Check in current code

- Supports incoming and outgoing TCP connections
- Examples updated to function as web server or client
Bring more in-line with Arduino Ethernet API

- Changes to use IPAddress instead of IP_ADDR for assignments to bring
more in-line with Arduino Ethernet API
- Update examples to demonstrate API changes
- Still seems to be some issues regarding stability or timing out,
generally during multiple large (KB+) data transfers via HTTP as a
client
Add multicast relay, modify TCP window handling

- Realized I hadn't enabled multicast relay, so outbound connections
were stalling out as soon as the initial ARP entry was lost for nodes
with parents other than master (00)
- Modify calls to uip_restart, to simplify auto re-opening of the TCP
window
Add documentation link to readme
Clean up examples
Clean up examples and config, add new example

- Clean up uip-conf.h file a bit
- Make output buffer size configurable via uip-conf.h
- Increase default restart time for TCP window reopening
Update Readme
Merge remote-tracking branch 'origin/master_dev'

Conflicts:
	README.md

Merging master-dev into master