Isolate document download speed from open speed in benchmark
Use the cached data if possible when finding the file size of a path

Note, this function returns the size of the file in bytes. For a string,
the length is not indicitive of the file size, therefore a lookup is required
to the server.
Merge pull request #205 from peitschie/benchmark-fixup-2

Isolate document download speed from open speed in benchmark
Update Closure compiler and more typechecking.
The type Runtime.ByteArray is removed. Uint8Array is used instead.
The more rigorous type checking is enabled by the flag --jscomp_error reportUnknownTypes.
To compile with this flag, build the target typecheck-target.
Revert CC for now.
More type fixes.

This patch also contains quite some cleanups and reorganization in runtime.js.
Fix loading of files via XHR.
Fix pointer to parent class.
Do not forget to set the value of sharedRange.
Add fallback for loading in IE.