minor, import and build libcoru, Michael Abbott's coroutine lib

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
chore, build glue for cattle(1) and libcoru coroutines

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, provide cattle(1) subcommand apply, utilising coroutines

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, migrate print subcommand to coroutines

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'feat/cattle-tool'

* feat/cattle-tool:
  minor, migrate print subcommand to coroutines
  minor, provide cattle(1) subcommand apply, utilising coroutines
  chore, build glue for cattle(1) and libcoru coroutines
  minor, import and build libcoru, Michael Abbott's coroutine lib