make: Add support for building bundles.
make: Add support for building bundles.

With this change, the make build can build frameworks and app bundles, if
the output path doesn't happen to contain spaces (i.e. chromium doesn't 
work quite yet).

For bundles, self.output is now the bundle directory, and self.output_binary
the binary within. For non-bundle targets, self.output and self.output_binary
are the same file.

For bundles, self.output depends on all bundle_deps to make sure they're
built before the bundle, and then package-frameworks is called for the
bundle.
Review URL: http://codereview.chromium.org/7396012

csulmone/gyp,csulmone/gyp,csulmone/gyp,csulmone/gyp