Split up the travis run into a unit-test shard and multiple IT shards.

Also move tests/python/pants_test/tasks/jvm_compile/java:test_java_compile_integration
out of the unit test suite.

Testing Done:
CI went green here: https://travis-ci.org/pantsbuild/pants/builds/40216412

Bugs closed: 773

Reviewed at https://rbcommons.com/s/twitter/r/1290/
what_changed: the build graph is sorted twice even though the first iteration does not require the targets to be sorted. Removing that sort reduces the call time by about a third in a non scientific test.

Testing Done:
ci.sh passes locally

Reviewed at https://rbcommons.com/s/twitter/r/1291/
Switch all remaining accesses of 'context.options' to new options.

Killed IvyUtils's dependency on options. It only needed it for
two options that no one is using in practice and this made things
much much simpler.

Also made some methods in IvyUtil classmethods, so that call sites
don't need to instantiate it and pass it config.

Testing Done:
All task unittests passed.

CI passed.

Reviewed at https://rbcommons.com/s/twitter/r/1289/
setup_repo: now only 98% impossible

This page was full of doom and gloom: Want to start using Pants? Might as well just give up.

Walk back some of that. Point out some files that you need to copy+adjust.

This probably still doesn't capture everything folks need, but it could be a step in the right direction.

rm the howto_customize page. For a while, I thought such a page would be useful... but its material all falls into setup_repo and howto_plugin.

Testing Done:
https://travis-ci.org/pantsbuild/pants/builds/40251344

Bugs closed: 632, 726, 776

Reviewed at https://rbcommons.com/s/twitter/r/1295/
Remove a bunch of setup_parser plumbing from goal/task.

reflect.py relied on the old options system via setup_parser, so
it's been broken for a while, ever since options migration began.
Fixed that by making it read from the new options.

Testing Done:
Manually ran the doc generator and inspected the resulting docs.

CI passed.

Reviewed at https://rbcommons.com/s/twitter/r/1297/