Move HelperFormatter into parsers()

If argparse is not installed, then the class
definition of HelpFormatter will fail if it's
at the top-level.
Use non-zero Stop rc for missing modules

This makes it clear that a missing module
execution in no way succeeded.
Merge pull request #1 from joshmoore/github

Minor changes for missing modules
merge master -D org -I include -E conflict -E needs-fixes -E broken: PR 47 (Auto submod updating)
merge master -D org -I include -E conflict -E needs-fixes -E broken: PR 49 (Check for proper "github" module)
merge master -D org -I include -E conflict -E needs-fixes -E broken: PR 50 (Handle KeyboardInterrupt on "Enter password")
merge master -D org -I include -E conflict -E needs-fixes -E broken: PR 52 (Filter improvement)
merge master -D org -I include -E conflict -E needs-fixes -E broken

Repository: openmicroscopy/snoopycrimecop
Already up-to-date.
Merged PRs:
  # PR 47 joshmoore 'Auto submod updating'
  # PR 49 sbesson 'Check for proper "github" module'
  # PR 50 sbesson 'Handle KeyboardInterrupt on "Enter password"'
  # PR 52 sbesson 'Filter improvement'

Generated by SCC-merge#122 (http://hudson.openmicroscopy.org.uk/job/SCC-merge/122/)