Update super to match latest spec.

`super()` now means call the proto of the current function.

Therefore we now need to be explicit with `super.method()`.
Fix issue with symbols and for of

With the experimental symbols option we need to expande for-of to
use $traceurRuntime.toProperty.

Fixes #1228
Rename file to have the correct case
Build directly out of node_modules/traceur.

We use the previous compiler from node_modules but
we were copying it into ./build based on old two-pass
self-hosting logic. Here we clean that up so we
have a better understanding of what we are really doing.

Review URL: https://api.github.com/repos/google/traceur-compiler/issues/1424

Closes #1424.
Evaluate modules using node-internal Module._compile() rather than eval.

...).

This allows require() to work alongside es6 import.

Review URL: https://api.github.com/repos/google/traceur-compiler/issues/1431

Closes #1431.
Fix return type assertions & arrow functions

Fixes #1443
Allow undefined/null as source for Object.assign

Fixes #1448
Add parsing support for type generics

Aka TypeArguments. The syntax is taken from the TypeScript spec
and here are some examples:

Array<number>
Map<number, boolean>
a.b<c, d.e, f.g.h>
Correct the relative path for traceur-loaded nodejs modules.

Using Module._compile() causes evaled code to require() relative to the
caller of _compile(). We want the require() to be relative to the file containing
the es6 code we transcoded.

Here we include a file-local function `require()` during transcoding of modules.
The local require() calls a runtime function with the module name and the required path.
The runtime function resolves the required path iff its relative.

Review URL: https://api.github.com/repos/google/traceur-compiler/issues/1434

Closes #1434.
Add missing file from previous commit.

TBR=@arv

Review URL: https://api.github.com/repos/google/traceur-compiler/issues/1454

Closes #1454.
Make types work in placeholder parser

This requires the parser to take an option object.
PlaceholderParser: Allow null in type context

This is so that you can do:

  parseStatement `var x: ${null};`

result in

  var x;
Add support for class member variable
Type asserts: Fix issues with TypeName and asserts

The assert functions we used for testing was wrong. It did not
handle number vs Number.

We also dropped the `moduleName` of the TypeName on the floor.
Add test case to verify compile to register format with name

Review URL: https://api.github.com/repos/google/traceur-compiler/issues/1470

Closes #1470.
Update README.md

Fixed link to wiki Getting Started page
0.0.73
Commit binaries for 0.0.74