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.