[rt.cpan.org 81497] Make a couple attributes lazy to avoid hash order issues.

Andreas Koenig reported a hash-order issue in Reflex.  I couldn't see
it, but Matt S. Trout pointed out that it's probably because some
trait attributes are too eager.  Here I make those traits lazy on his
recommendation.  Tests pass.  Will commend it to the CPAN testers for
further evaluation.
Fix a method name typo.
[rt.cpan.org 83718] Implement a start method for Reflex::Role::Interval.

Pointed out by CPAN user MBETHKE.