async,promises: initial tests of Promises

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