LogManager implementation is modified to use ManagedLogger, which can swap out backing Appenders without re-creating the log instance.
The State was also changed to track `currentCommand: Option[Exec]`. `Exec` knows the origin of the command invocation, and using that we can now send the network-originated events only to the network clients.
Combined together, this implements log splitting between the sbt clients (channels).
Cherry-picked 84cba9669c from branch 0.13 to 1.0.x
Tested manually:
$ grep 'version.*:=' build.sbt
version := "0.13.10-SNAPSHOT",
$ git archive --prefix=sbt-0.13.10-SNAPSHOT/ -o ~/Desktop/sbt-0.13.10-SNAPSHOT.tgz HEAD
$ cd ~/Desktop
$ ls
sbt-0.13.10-SNAPSHOT.tgz
$ tar xfz sbt-0.13.10-SNAPSHOT.tgz
$ cd sbt-0.13.10-SNAPSHOT/
$ sbt info
[info] Loading global plugins from /Users/dnw/.dotfiles/.sbt/0.13/plugins
[info] Loading project definition from /Users/dnw/Desktop/sbt-0.13.10-SNAPSHOT/project
[info] Updating {file:/Users/dnw/Desktop/sbt-0.13.10-SNAPSHOT/project/}sbt-0-13-10-snapshot-build...
[info] Resolving org.fusesource.jansi#jansi;1.4 ...
[info] Done updating.
[warn] There may be incompatibilities among your library dependencies.
[warn] Here are some of the libraries that were evicted:
[warn] * com.typesafe.sbt:sbt-site:0.8.1 -> 0.8.2
[warn] Run 'evicted' to see detailed eviction warnings
[info] Compiling 12 Scala sources to /Users/dnw/Desktop/sbt-0.13.10-SNAPSHOT/project/target/scala-2.10/sbt-0.13/classes...
[info] This is sbt 0.13.9
[info] The current project is {file:/Users/dnw/Desktop/sbt-0.13.10-SNAPSHOT/}sbtRoot 0.13.10-SNAPSHOT
[info] The current project is built against Scala 2.10.6
[info] Available Plugins: sbt.plugins.IvyPlugin, sbt.plugins.JvmPlugin, sbt.plugins.CorePlugin...
[info] sbt, sbt plugins, and build definitions are using Scala 2.10.5
Dale Wijnand
Eugene Yokota