Detect nested stage-scripts and indent output accordingly

[jmgate]

It'd be really nice if a StagedScript could detect whether it was being run within the stage of another StagedScript, and, if so, adjust it's output by prepending an indent level. I have no idea how I might implement such a thing at the moment, but seeing the output of one script run by another is confusing for the user, because they just see all the stages consolidated together into a flat level, which can be misleading. E.g., consider just the stage headings in the output:

Opening project...
Building documentation...
Creating an environment...                                     # This is a nested script,
Installing documentation dependencies...                       # but the user is unaware,
Building documentation...  # Didn't we already do this above?  # because the output doesn't say.
Building toolbox...
Cleaning up...