Clarify compileall command-line options (#10454).
Clarify compileall command-line options (#10454).

Backport of R. David Murray’s 3.2 patch.  The code is ugly, with print
statements split across lines, but the output is readable.

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator