use Scala 2.10.1 final
note that mixing RangePositions into Global isn't necessary in 2.11
toString for Stamp types
Logger.Null that discards logged messages
Provided details of why external binaries are detected as modified in incremental compiler debug output.
Remove the conflict warnings based on the evicted modules. Ref #709.

This aspect is better served by a standard Ivy conflict manager.
Docs: latest change summary, including 0.12.3-RC2
temporary option to disable classpath lookup in incremental compiler.  Ref #710.