improve review scripts

[joachimmetz]

• Fix git pull issue on close
• fix version not being updated on merge
• Check why the rietveld close issue is still not working
  • missing cookie jar - use OAuth instead
• change/remove missing test file script
• Move review scripts to Python - to support Windows
  • update l2tdevtools script with plaso scripts
  • fix limitation in merge script that CL description cannot contain a ':'
  • add a submitted comment to code review
  • change http:// to https:// where possible
• fix issue argparse yielding different results when run from review.py
• review.py add functionality to "test"
• review.py add option for unattended mode - do not ask for confirmation
• review.py create - do not generate '[project_name]' in PR description
• document usage of BROWSER environment variable
• review.py "lint" add option to lint all files
• update dfwinreg scripts
  • removed shell scripts
• update dfvfs scripts
  • removed shell scripts
• update plaso scripts
  • removed shell scripts
• Provide pylint in l2tbinaries
• https://codereview.appspot.com/309000043/
  • create - check if review file exists first
  • close - notify if review file is missing or codereview issue cannot be closed
  • close - support user:branch as input besides branch
  • added update-authors functionality
• add lint_and_test option
• fix issue with create --nobrowser
  • Create aborted - unable to create codereview issue.
  • Issue created message not at the start of the line

Remaining items moved to: https://github.com/log2timeline/l2treviewtools/issues/22

[rgayon]

Only run python tests when python code was modified