Licenses
Makefile from fabric-tofino
Move P4 code to src/main/p4
Add PipeconfLoader and pom file

Add bridge metadata and use different metadata for ingress and egress
metadata.

Supports basic fabric functionality:
 - packetio
 - IPv4 unicast
 - MPLS
 - L2 bridging

Work in progress:
 - multicast
 - double vlan tagging
 - IPv6 unicast

 - remove unused comment
 - fabric -> fabric-tna

The new Stratum fixed the CPU port issue

 - add new device "stratum-bfrt" to PTF
 - restructure repo
   - move p4 source code to /p4src
   - new script to build pipeline tar
 - add new pipeconf for stratum_bfrt
   - Needs "RAW_DEVICE_CONFIG" extension support
- update PTF test script
- custom flags for stratum-bfrt docker container
- Use stratum-bfrt as the default stratum binary

Added instructions on how to obtain and load the stratum-bfrt docker image. Also, I moved instructions for setting `STRATUM_BF_DOCKER_FLAG` as an optional last step, as that was preventing the stratum container to start (it was looking to mount `abs-path-to-stratum_bfrt` which didn't exist on my machine).

Apart from this, instructions work well. I was able to run all tests (excluding multicast and packet I/0 for which we don't have support yet).

bfrt_python CLI will use pipeline name as a variable name in shell.
We cannot use a name with "-" as a variable.