OS-2645: IMGADM_LOG_LEVEL support for controlling imgadm logging
OS-2561: vmadm should allow filtering by firewall_enabled
OS-2645: style / lint fixes
OS-2646: vmadm: updating firewall_enabled=true errors out with "select attr: No such resource with that id"
OS-2649: fwadm should not require files in /usr/node/node_modules
OS-2651: 'imgadm create' wipes out given manifest.requirements
OS-2652: imgadm should include identifying User-Agent in IMGAPI requests

Also change polling interval from 1s to 2s for 'imgadm create' polling
on prepare-image:state.

This is imgadm 2.6.1.
fix 'make check'
IMGAPI-312: *smartos* 'imgadm create' set min_platform to the current platform version

Also fix a breaking in the test suite due to IMGADM_LOG_LEVEL
and '-v' changes a short while ago.
OS-2653 sysinfo is n^2 in disk count
OS-2655: imgadm should run with --abort_on_uncaught_exception
NET-229: setting "allow_ip_spoofing":true via vmadm strips off the "primary" nic designator, if it's not in your json
add props.js to gitignore, load sysinfo when needed.
merge from master