3605: Add properties column to node.  Put public-facing node information (cpu
cores, RAM, scratch space) into properties field.  Info field is back to being
admin-only.
3605: Do .to_i on total_cpu_cores, total_ram_mb, and total_scratch_mb in Node#ping.
Merge branch '3605-node-info-field' refs #3605

Conflicts:
	services/api/db/structure.sql