Benjy Weinberger got a fish trophy!

Remove all global config state.

Review Request #2222 - Created May 14, 2015 and submitted

Benjy Weinberger
jsirois, zundel

- No more config cache.
- No more global default bootstrap options, so also no dynamic
resetting of those...
- Removed many superfluous BUILD dependencies on the config library.
- test_gen_tasks_options_reference_data no longer broken.

There are now only 4 deps on config in the entire codebase:
1. The options system depends on it, of course.
2. The migrate config script.
3. Android keystore code, which uses it to reads its own config
(which has nothing to do with the main pants config).
4. Its unittest.

So this commit completes the process of switching everything over
to new-style options. It should now be possible (with maybe some
tweaking of defaults) to run pants with an empty pants.ini.
I have not tried this... :)

Actually, the above statement is not quite true: backends are still read
directly from config.

CI, amazingly, passed on the first attempt:

Benjy Weinberger
Eric Ayers
Eric Ayers
John Sirois
Benjy Weinberger
Review request changed

Status: Closed (submitted)

Change Summary:

Submitted as 9bd9f7fd6942526bcb69200376ff35426e61c6a3. Thanks Eric and John!