Broke logic into functions to make more readable, support executing without a configuration file.
Updates to fix problems executing without a config file, reporting an error when pip calls fails.
Major changes.  Merge in sitepkg_install option code from Milwaukee.
Add download_cache_dir and sitepkg_install options.  Fix issues related to
implicit package revisions.
Add support for download_cache_dir.  Handle case where no config file is specified without immediately erroring.
Updates to handle specifying the pypi_pull_server as a file:// URL (to bootstrap a VM from a set of cached packages).
Fix bug with _get_newest_package_version_and_url().
Added --helper-scripts option to allow OS specific scripts / batch files to
assist with using virtualenvs to be created.  --helper-scripts currently
only supports Windows, will do nothing for other OSes.
Added --download_dir command line option, improved operation when
using a download or download cache dir.
Added --noupdate option, fix issues with site-package installs.
Add pypi_push_no_cert_verify configuration file option to fruit_orchard, and
code related to passing this information on.
Merge branch 'master' into virtualenv_refactor_01

# By Matthew Tardiff (55) and James Carpenter (6)
# Via Matthew Tardiff (3) and James Carpenter (1)
* master: (61 commits)
  Flake8-ed
  tweaked virutalenv_util.py to ensure compliance with flake8
  tweaked setup.py files to ensure flake8 compliance
  ran find script to fix newlines affecting flake8
  manually fixed remaining flake8 errors in pypi_redirect
  fixes using matt's find script
  fixed flake8 errors
  PEP8-ed the examples.
  PEP8-ed daf_fruit_dist and daf_fruit_seed. Skipped daf_fruit_orchard since it will be merged with some other code later.
  Renamed missed instances from the previous four commits.
  Renamed missed instances from the previous three commits.
  Renamed missed instances from the previous two commits.
  Renamed missed instances from the previous commit.
  Renamed "python_garden" to "examples". Prefixed fruit_dist, fruit_orchard, fruit_seed, pest, fruit, apple, citrus, and basket with "daf_".
  Fixed URL in setup.py meta-data and added description and keywords.
  Fixed link in setup.py and added some important missing fields.
  Peer reviewed.
  Added proxy tests.
  Added "python/" Artifactory tests for the cached cases.
  Refactored get-and-validate package tests.
  ...

Conflicts:
	defend_against_fruit/daf_fruit_orchard/daf_fruit_orchard/virtualenv_util.py
	defend_against_fruit/daf_fruit_seed/virtualenv_util_bootstrap.py
flake8-ed daf_fruit_orchard and daf_fruit_seed.
Examples and pypi_redirect now rely on the 1.2.91 of daf.