Adding support for AppRTC closure compiling.

Since AppRTC now uses Closure we need to be able to closure compile.
This is implemented as a grunt task, which means we need grunt, which
means we need node and npm. This patch makes sure to download all the
necessary dependencies and invokes them locally, which means we don't
need to install stuff on the bots. A risk here is increased flakes
since many of these tools (like npm) download stuff in a manner that
likely isn't reliable. I suggest we check how it works out and add
retry mechanisms as necessary.

This checks in node versions
node-v0.10.35-linux-x64.tar.gz / v0.10.36/x64/node.exe

into source control.


Review URL:

git-svn-id: 4ff67af0-8c30-449e-8e8b-ad334ec8d88c
10 files changed