Expose Ivy's circular dependency check via UpdateOptions
Bump to a version of ivy that will not swap in httpclient URL handler.

When ivy finds the httpclient on the classpath, it will silently change
its url handler, and the httpclient in ivy 2.3.x has a few known
issues.
Merge pull request #1601 from sbt/wip/circular

Expose Ivy's circular dependency check via UpdateOptions
Add notes for this fix.
Merge pull request #1602 from sbt/wip/ivy-no-commons-httpclient

Bump to a version of ivy that will not swap in httpclient URL handler.
Merge pull request #1590 from jedesah/0.13

Add developer key
Fix #1598 - Ivy fails to load evicted information.

Upgrade to a version of ivy 2.3.0 that has a backported fix for conflict resolver.
Merge pull request #1607 from sbt/fix/1598-2

Fix #1598 - Ivy fails to load evicted information.