Conda

Improvements
* add "error" key back to json error output (3523)

Bug Fixes
* fix 3453 conda fails with create_default_packages (3454)
* fix 3455 --dry-run fails (3457)
* dial down error messages for rm_rf (3522)
* fix 3467 AttributeError encountered for map config parameter validation (3521)

Deprecations/Breaking Changes
* revert to 4.1.x behavior of `conda list --export` (3450, 3451)

Bug Fixes
* don't add binstar token if it's given in the channel spec (3427, 3440, 3444)
* fix 3433 failure to remove broken symlinks (3436)

Non-User-Facing Changes
* use install.rm_rf for TemporaryDirectory cleanup (3425)

Improvements
* add support for client TLS certificates (3419)
* address 3267 allow migration of channel_alias (3410)
* conda-env version matches conda version (3422)

Bug Fixes
* fix 3409 unsatisfiable dependency error message (3412)
* fix 3408 quiet rm_rf (3413)
* fix 3407 padding error messaging (3416)
* account for the Windows Python 2.7 os.environ unicode aversion (3363 via 3420)

Deprecations/Breaking Changes
* partially revert 3041 giving conda config --add previous --prepend behavior (3364 via 3370)
* partially revert 2760 adding back conda package command (3398)

Improvements
* order output of conda config --show; make --json friendly (3384 via 3386)
* clean the pid based lock on exception (3325)
* improve file removal on all platforms (3280 via 3396)

Bug Fixes
* fix 3332 allow download urls with :: in them (3335)
* fix always_yes and not-set argparse args overriding other sources (3374)
* fix ftp fetch timeout (3392)
* fix 3307 add try/except block for touch lock (3326)
* fix CONDA_CHANNELS environment variable splitting (3390)
* fix 3378 CONDA_FORCE_32BIT environment variable (3391)
* make conda info channel urls actually give urls (3397)
* fix cio_test compatibility (3395 via 3400)

Bug Fixes
* fix 3277 conda list package order (3278)
* fix channel priority issue with duplicated channels (3283)
* fix local channel channels; add full conda-build unit tests (3281)
* fix conda install with no package specified (3284)
* fix 3253 exporting and importing conda environments (3286)
* fix priority messaging on conda config --get (3304)
* fix conda list --export; additional integration tests (3291)
* fix conda update --all idempotence; add integration tests for channel priority (3306)

Non-User-Facing Changes
* additional conda-env integration tests (3288)

Improvements
* added zsh and zsh.exe to Windows shells (3257)

Bug Fixes
* allow conda to downgrade itself (3273)
* fix breaking changes to conda-build from 4.2.2 (3265)
* fix empty environment issues with conda and conda-env (3269)

Non-User-Facing Changes
* add integration tests for conda-env (3270)
* add more conda-build smoke tests (3274)