DM
Fixes
* Changes the test ClassLoader so it won't close by default, and reverts the ClassLoader layer created specifically for ScalaTest #5327 / #5308 by @eatkins
* Fixes sbt shell script not working the first time it's invoked on JDK 11 sbt/sbt-launcher-package#313 / #5270 by @eed3si9n
* Works around subproject named clean getting mixed up with client command #5317 / #5314 / #5265 by @eed3si9n
* Fixes cross command + so the tasks run in parallel when possible #5329 / #5321 by @eatkins
* Fixes installer missing some artifacts sbt/sbt-launcher-package#310 by @eed3si9n
* Fixes sbt.bat so -debug option is processed first sbt/sbt-launcher-package#311 by @er1c
* Fixes sbt shell script to reduce the number of flags passed into rsync sbt/sbt-launcher-package#316 / #5035 by @eed3si9n

