Exit workers on sigint rather than ignore

Testing Done:
https://travis-ci.org/pantsbuild/pants/builds/42139656

Also: ctrl-c'ed in the middle of cache fetch with and without this change.

Without: observe dots continue to print for several seconds after main process appears to exit. `killall python` required to stop them.
With: dots stop printing immediately, no python processes running.

Bugs closed: 829

Reviewed at https://rbcommons.com/s/twitter/r/1405/
Patch up migrate_config

- Patch up migrate_config with missing dependency.
- Move partition_size_hint into the correct section in pants.ini as pointed out by migrate_config
- Fix the 'target' and 'source' config options for [compile.java] (remove quotes)

Testing Done:
Before adding this dep, got:

  File "/Users/zundel/Src/pants/dist/migrate_config.pex/pants/option/migrate_config.py", line 13, in <module>
ImportError: cannot import name custom_types

when trying to execute migrate_config.

Bugs closed: 832

Reviewed at https://rbcommons.com/s/twitter/r/1409/
Fix antlr package derivation.

Also fixup jvm tool integration tests to respect
TMPDIR being on a different device than the build root.

Testing Done:
$ PANTS_DEV=1 ./pants goal list tests/python/pants_test/tasks: | grep antlr | PANTS_DEV=1 xargs ./pants goal test

CI went green here: https://travis-ci.org/pantsbuild/pants/builds/42654357

Bugs closed: 833

Reviewed at https://rbcommons.com/s/twitter/r/1410/