Add patch to disable sandbox in SharedWorker.
Do not contain the Debug build in distribution.

It would saves a lot of time when uploading & downloading on a slow
network, and in the atom branch the debug build is not actually used
too.
Do not export symbols in chromiumviews.

In atom-shell there are too many symbols in chromiumviews that caused
the linker to excceed the symbols number limit when generating the
node.lib.