move 3rd party packages under dbsake.thirdparty namespace

- this includes 'sarge' (used for pretty subprocess access) and
  'tempita' used for templating
remove argparse

- dbsake was not using any argparse features and this adds about
  ~20KB (compressed) to the executable zipfile.  Removed argparse
  and adjusted dbsake:main() to use optparse instead.
bump version to 1.0.4
Merge branch 'feature/thirdparty_cleanup' into develop
add versionadded:: 1.0.3 tag to mysql-sandbox documentation