Add Swift Static Large Objects to admin guide

Grizzly brings a new feature to swift - the ability to upload
large objects broken into chunks, unified by a manifest file.
This patch copies the doc from the swift code into the admin
manual.

fixes bug 1153469

Change-Id: Ib3cd45d9d3e2dd8ddd151a5a1acde14639af4b83
Merge "Add Swift Static Large Objects to admin guide"