make it clear: you can only download those pexes because you previously uploaded 'em.

they don't appear by magic.

Reviewed at https://rbcommons.com/s/twitter/r/1296/
Ensure that the new options system reports goals in the right order.

We sometimes rely on this, e.g., when specifying "clean-all compile".

Testing Done:
option unittests pass. CI passed when run with https://rbcommons.com/s/twitter/r/1309/

Reviewed at https://rbcommons.com/s/twitter/r/1308/
Switch option parsing for goals to the new parser.

Relies on https://rbcommons.com/s/twitter/r/1308/.

Testing Done:
CI passed when run with https://rbcommons.com/s/twitter/r/1308/.

Reviewed at https://rbcommons.com/s/twitter/r/1309/
Add support for the Wire protobuf library.  Adds the java_wire_library() target.

https://github.com/square/wire

Testing Done:
Added an example, plus new unit and integration tests.
CI is running @ https://travis-ci.org/pantsbuild/pants/jobs/39988400

Bugs closed: 765

Reviewed at https://rbcommons.com/s/twitter/r/1275/
Remove some remaining old options references.

Testing Done:
CI passed. Manual testing of cmd-line flags.

Reviewed at https://rbcommons.com/s/twitter/r/1317/
docs: confluence-publish's wiki info lives in a plugin now.

also, give a sample ConfluencePublish goal.

Bugs closed: 723

Reviewed at https://rbcommons.com/s/twitter/r/1299/
doc: update import path for PEX

"I don't see any code still importing twitter.common.python pex (except for examples in rst files,which should probably be fixed)"

Bugs closed: 428

Reviewed at https://rbcommons.com/s/twitter/r/1298/
switch src/* usages of Config.load to use Config.from_cache instead

Now all usages of Config.load in src use a cache if the config already has been parsed.

This doesn't change test usages, but since tests use temp directories, tests with different ini files don't interfer

Testing Done:
ran ci.sh locally

travis ci in progress: https://travis-ci.org/pantsbuild/pants/builds/40687043

Bugs closed: 788

Reviewed at https://rbcommons.com/s/twitter/r/1319/
- Create VIRTUALENV_PACKAGE_LOCATION env var so we can customize virtualenv package download
- Refactor to have a common.sh containing the set_archflags and logging functionalities.
- Make the virtual env script a bit more robust against curl/tar/activate errors

Testing Done:
manually tested:
1) not specifying VIRTUALENV_PACKAGE_LOCATION,
2) specifying a valid custom VIRTUALENV_PACKAGE_LOCATION location, and
3) specifying an invalid VIRTUALENV_PACKAGE_LOCATION location.

Travis: https://travis-ci.org/jinfeng/jinfeng-pants-fork/builds/40690744

Reviewed at https://rbcommons.com/s/twitter/r/1316/
Skip compressing/writing artifacts that are already in the cache.

Compressing things is expensive, so no reason clients should do it if they don't have to and writing the same thing over and over wastes IO capacity on the cache server.

Testing Done:
https://travis-ci.org/pantsbuild/pants/builds/39729173 passed

Bugs closed: 760

Reviewed at https://rbcommons.com/s/twitter/r/1272/