Stop committing bin/traceur.js to git.

We now use npm to obtain a last-good compiler for self-builds.

Review URL: https://github.com/google/traceur-compiler/pull/1098

Closes #1098.
Fix issue with temp variable transformer and multiple this

The temp var transformer was storing the this temp bindings on the
wrong scope object.

This renames the methods to make the two different scopes clearer.

Fixes #1086
Lock options on Compiler classes and make them read-only.

Rework API to work better with single-inheritance.
Replace uses of tracuer.compile with node api.js compile.

Change the default for option moduleName to false
remove logging
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