Part of 28863.

Part of 28863.

Use Xenial for pypy.

Part of 32632 and 28863.

Use Ubuntu Bionic and macOS 10.14.

Install Homebrew python@2 in macOS
macOS needs pip(2) to install fallback scripts dependencies.

Part of 32632 and 28863.

* Restrict the valid True and False bool values
* use default for unset env var, and (not default) for empty set env var

Closes 31305.

Part of 31305.

Also add a requirements.txt

Initial implementation of #28979.

Tested with:
TOR_FB_ONIONOO_LIMIT=200 ./updateFallbackDirs.py

Part of 29100.

Tested with:
$ TOR_FB_MAX_FALLBACK_COUNT=10 ./updateFallbackDirs.py check_existing
$ TOR_FB_MODE=check_existing TOR_FB_MAX_FALLBACK_COUNT=10 ./updateFallbackDirs.py

Part of 29100.

Tested using:
$ TOR_FB_MAX_FALLBACK_COUNT=10 ./updateFallbackDirs.py

Part of #29100.

And remove a duplicate "import re".

Part of 29100.

Closes 28986.
Patch by starlight, edited by teor.

Part of 29100.

Part of 29100, but these files are created by the scripts in 28794.

Closes 30948.

Closes 30947.

Closes 29100.

Tested with:
TOR_FB_ONIONOO_LIMIT=200 ./updateFallbackDirs.py

Part of 29100.

Tested with:
$ TOR_FB_MAX_FALLBACK_COUNT=10 ./updateFallbackDirs.py check_existing
$ TOR_FB_MODE=check_existing TOR_FB_MAX_FALLBACK_COUNT=10 ./updateFallbackDirs.py

Part of 29100.

Tested using:
$ TOR_FB_MAX_FALLBACK_COUNT=10 ./updateFallbackDirs.py

Part of #29100.

And remove a duplicate "import re".

Part of 29100.

Part of 29103.

Remove the parts of the LICENSE that only apply to external source code
distributed with Tor, and edit the header.

Rewrite the README with specific information about the Tor Fallback Scripts.

Closes 29103.

Part of 29103.

Part of 28794.

Closes 28986.
Patch by starlight, edited by teor.

Part of 29100.

Part of 29100, but these files are created by the scripts in 28794.

And:
* remove orphaned old sources
* remove fallbacks that can't be added
  (we'll contact their operators separately)

Closes 28984.

$ python generateFallbackDirLine.py `grep -v -e "#" -e "^$" update_add.txt | tr "\n" " "` >> fallback.whitelist

See this commit's diff for the list of fingerprints, and the results.

Part of 29794.

See the previous commit for the script.
See this commit's diff for the (long) list of relays.

Part of 28794.

$ cat << EOF > remove.txt
36B9E7AC1E36B62A9D6F330ABEB6012BA7F0D400

FC9AC8EA0160D88BCCFDE066940D7DD9FA45495B
ACD889D86E02EDDAB1AFD81F598C0936238DC6D0
EOF
$ mv fallback.whitelist fallback.whitelist.old
$ grep -E -v `grep -v -e "#" -e "^$" remove.txt | tr "\n" "|"; echo -n dummy` fallback.whitelist.old > fallback.whitelist

(Some day we should turn this into a python script.
But that day is not today.)

Part of 28794.

Closes 30948.

Closes 30947.