Respect dep order in the breadth 1st dep walk.

This change led to a zinc error claiming jline was incompatible.
Notably, the custom jline dep in BUILD.tools was now 1st on the
classpath.  It turns out zinc / scala-compiler pulls in a jline
on its own so kill the un-needed jline dep.

https://rbcommons.com/s/twitter/r/156/