ForestDB Silent corrupts by-seq-index when seqs are insert in the wrong order.

Problem
ForestDB expects seqno to be inserted in monotonic order. When a document is insert with a seqno that is already used or below the current high seqno. It will accept the document, unfortunately it will corrupt the by-seqno index. This meaning that when iterating over the database using the seq-no it will not return a document for that seqno.

Expectations
For the write to be not accepted.