Persistent HWaddr for bat0
Added .gitignore file to ignore build dir
Added builddir - do all rpi image building there
Two interested locations.
Generated.
Merge pull request #4 from olekvi/build-rpi-image-in-build-dir

Build rpi image in build dir
Merge pull request #2 from bfg1981/master

Persistent HWaddr for bat0
Store bat0 MAC address in /var/lib/meshfx-node/bat0, not /var/tmp/bat0.