Check for object autoImport in auto plugins. Fixes #1314
Merge pull request #1318 from sbt/topic/1314

Check for object autoImport in auto plugins.
Updated on Changes.rst
Back out autogc fix to be optionally enabled.

Workaround for #1329
Modify changes with latest RC changes.
Merge pull request #1332 from sbt/wip/disable-force-gc

Default force gc to false
Merge remote-tracking branch 'origin/0.13.5' into wip/merge-0.13.5

Conflicts:
	main/src/main/scala/sbt/EvaluateTask.scala
Merge pull request #1334 from sbt/wip/merge-0.13.5

Wip/merge 0.13.5