Removed 'authoritative' flag

Shouldn't be controversial, I think we talked about removing this in 0.95 but just forgot to.

For those new to the discussion: this is a holdover from when the LRS was "smarter" than it is now -- we've decided it's up to systems reading statement to decide how to weigh statements.
Merge pull request #88 from bscSCORM/nonauthoritative

Removed 'authoritative' flag