* Re-adjust canonical head to parent of block to be inserted
why:
of the failing tests that remain to be solved, 30 of those will succeed
if the canonical database chain head is cleverly adjusted -- yes, it
looks like a hack, indeed.
details:
at the moment, this hack works for the non-hive tests only and is
triggered by a boolean argument passed on to the chain.persistBlocks()
method.
* Use parent instead of canonical head for block to be inserted
why:
side chains need to be inserted typically somewhere before the
canonical head.
details:
the previous _hack_ was unnecessary and removed, it was inspired by
some verification in persistBlocks() which explicitly referenced the
canonical head (which now might or might not refer to the newly inserted
header.)
* remove unnecessary code + comment
Jordan Hrycaj
jangko