use Object.defineProperty to provide a Symbol.create impl, instead of an assignment.  fixes #161
Fixed an ES5 strict test that crashes in Chrome

The test `(function f() { f = 123; })()` actually throws a SyntaxError
on evaluation, not a TypeError on execution, in the current Chrome. I'm
really not sure which is fully correct for either the ES5 or ES6 specs.
Nevertheless, I've changed that line to be eval()ed so that the entire
script doesn't crash.

Also, the link to the strict mode page is fixed.
ES6 test functions in multi-line strings

This updates the build script, allowing it to interpret ES6 code
expressed in function comments instead of concatenated strings (see #190
discussion) - which is then wrapped in try-catch, eval() and test()
structures automatically.

Also, the runtime script has been updated to unwrap those same
structures for the tooltip preview, making the resulting display cleaner
- lacking even the test() call wrapper.

Only some ES6 and non-standard tests have been converted to make use of
this format, for the moment. The remaining tests are subject to
pull-requests at this moment and will be addressed after those are
resolved.

NOTE: as this drastically affects the output of all HTML files, they
have not been included in this commit, to allow merging to pass
smoothly.
Updated/fixed some tests

Converted these tests to multi-line comment strings: super, defaults,
modules, generators, octal and binary literals, template strings. And on
the non-standard side: array comprehensions, for each..in, and generator
comprehensions.
Tooltip preview code now stored as data attr

Instead of converting the innerHTML of the <script> attribute at
runtime, the code is now stuffed onto a HTML attribute on the <script>
element at build time.

Also fixed some whitespace.
Updated some more tests to multi-line strings

Also fixed some capitalisation inconsistencies and updated some old
links.
Added notes to {__proto__} test

Firefox incorrectly allows the __proto__ syntax to affect shorthand
methods and shorthand properties, when in reality it only affects the
PropertyName : AssignmentExpression production.

Also added a check to ensure that __proto__ works with null. The results
were not affected by this.
Updated README.md
Merge pull request #209 from webbedspace/test-code

ES6 test functions in multi-line strings
Merge pull request #223 from webbedspace/null_proto_literals

Added Firefox notes to the {__proto__} test
Merge pull request #196 from webbedspace/strictmode

Fixed an ES5 strict test that crashes in Chrome
Merge pull request #163 from toshok/Symbol.create-fix

use Object.defineProperty to provide a Symbol.create impl.  fixes #161
Build html files
Add exponentiation operator to ES7 table. Closes #179
Added 2 extra let tests

These tests check for the temporal dead zone, and correct for-loop
iteration bindings. They are distinct from the basic let-test, as they
represent more advanced or nuanced functionality.
Altered the TDZ test to include const

Both const and let are subject to the temporal dead zone.
Fixed a small bug

Also updated IE11 support for for-loop iteration scope.
Const test now checks that assignment is an error

Assigning to a const should be a syntax error. This commit does not
update the test results to match this stricter test, yet.

This also fixes tabs introduced in previous commits.
Updating const results

Almost everything fails this updated test by treating const reassignment
as a silent failure instead of a syntax error.
Updated TDZ test results

Also fixed a bug in the Node test script.