Minor revisions to dx-{download,upload}-all-* help messages.

Summary: Also format the help strings a bit more nicely in the source code.

Test Plan: Manually examined output of running both scripts with -h.

Reviewers: orodeh, klai

Reviewed By: klai

Differential Revision: https://phabricator.dnanexus.com/D31
Fix line wrapping of option help after turning on RawTextHelpFormatter
Test fix for bash helpers
PTFM-12437: Adding a wrapper for whoami calls
Fix logging of messages that are close to the 8KB datagram limit
Changelog and version updates for v0.108.0
Accept 503 responses even if they don't have Retry-After set.

(cherry picked from commit 39e17aebfed4684c617845766b5d60af248a31af)
Show more helpful stacktrace for exceptions raised by DXHTTPRequest.

Still needs some work to avoid producing a lot of noise, though. WE
SHOULD PROBABLY NOT LET THIS GO TO PRODUCTION IN ITS CURRENT STATE.

(cherry picked from commit fe5689b9142c420fcf9185cb54a4f223105d4151)
Changelog and version updates for v0.108.1
Print non-ASCII URLs correctly in error messages.
Revert "Print non-ASCII URLs correctly in error messages."

This reverts commit cd922c77ad171143861c22b9d2055239f6c26246.
Revert "Show more helpful stacktrace for exceptions raised by DXHTTPRequest."

This reverts commit 9affee47e9b163d3cbb8f95f67301e846d9ce487.
Changelog and dxR version update for v0.108.2