Introduce configuration to allow build servers provided by the Travis CI
service to execute the test generation tool and commit the resultant
files to the canonical upstream repository.

Enabling this workflow required additional administrative work:

1. Create an account with TravisCI
2. Install the `travis` command-line utility
3. Create a "deploy key" and an encrypted version using the command
   `./make.py github_deploy_key_enc`
4. Register the deploy key with the project's GitHub account
5. Check the encrypted deploy key to the repository
6. Configure the TravisCI service to automatically build this project

doneprintHandle.js: make $DONE accept any falsy argument as meaning 'pass'
PromiseHelper.js: checkSequence: new helper fn for async tests
.gitignore: port .hgignore to .gitignore syntax
test262.py: support $INCLUDE directive in python test runner

S25.4.4.1*: tests to cover Section 25.4.4.1, Promise.all( iterable )
A1.1: Promise.all is callable
A1.2: Promise.all expects 1 argument
A2.1: Promise.all([]) is a Promise
A2.2: Promise.all([]) is resolved immediately
A2.3: Promise.all([]) is resolved with a new empty array
A3.1: Promise.all expects an iterable argument