This adds a few features:
* Parallel execution (and all other golang test runner features)
* Colored diffs of output
* Make and kati run in subdirs, all output is preserved
* Full logs saved of raw and normalized output per-testcase
* TODO(c/<testcase>) support to mark individual testcases as expected
  failures, instead of the full test.

Removed support for the [go]kati serialization tests

Change-Id: Id6be80a3168ccff3fa3a970fe089986f1aa066dd

Refactor out parts of run_make_tests to be reused by run_sh_tests so
that run_sh_tests can report expected failures.
Also expand the TODO regexp to support #!/bin/bash before the # TODO.

Change-Id: I2d2cc9b7999829ab9c8eeaa36edaf5ab732bd5bc

* Fix the code, add the test.
* Add a quiet mode for running the tests (only the failing tests will be
shown).

There's a flag to Soong in order to use bionic as a libc instead of
glibc, removing dependencies on your host system. This fixes a single
include what you use, and some error message differences.

This adds new (WARN|KATI_WARN|ERROR)_LOC log macro variants that take a
location as the first argument, and will prefix that location
information to the warning/error lines.

When --color_warnings is enabled, it reformats them to have a standard
warning:/error: infix, and adds colors in order to match the
warnings/errors produced by clang.

for issue #68

Also use override in tests which set $(SHELL)