Discovered a performance problem on Vista in 6u5 b05 PIT build.

Problem is because now we removed lib/zi core from the kernel core:
6601650: Remove lib/zi from Kernel core

So lib/zi needs to be downloaded on demand as a bundle.

Problem is this bundle contains over 400 individual files. So when this bundle gets installed in Vista, current implementation is to unzip the unbundle into the locallow tmp location first, and then move each individual files into the correct location. This becomes very slow, because it involves over 400+ IPC message exchange between the broker and the java process, in order for this bundle to be installed.

And there is no UI shown during the file move, so the user really don't know what's going on. After these 400+ files get installed, everything will continue as normal.

We should probably change the broker process to move the whole subdirectory at once, instead of moving each individual files separately.