Implement ONEAudit: Overstatement-Net-Equivalent Risk-Limiting Audit

[nealmcb]

Arlo should implement Overstatement-Net-Equivalent Risk-Limiting Audit: ONEAudit
as a more efficient alternative to batch auditing.

They can be especially efficient for contests in which results in any given precinct tend to be relatively homogeneous, i.e. where geographical divisions in how people vote are significant.