Support automatically opening test HTML in browser

When using the '-g' option with run_from_console.js, you can
now pass the '-o' option to automatically open the generated
HTML file in your default browser.  This relies on the 'open'
NPM module.
Add support for injecting test helper files

Now, the phrase `requires test modules: ` may be place in a comment
in a file to require modules local to the test directory, similarly
to the way the `require local modules: ` line may be used to inject
files in the 'include' directory.  This is useful for when common
fakes need to be injected into a test.
Fixed typo in run_from_console.js
Output error events from provider in test runner

Now, 'error' events from the test runner are output to stderr.
Additionally, when debug is enabled, debug output is logged to
stderr instead of stdout (as was the case previously).
Fix race condition in test runner

Previously, there would be a case where if your tests took
too long to run, the casper test runner would only report
on certain tests.  This has been fixed.