Drop the following flags that were deprecated already in v0.8.0:
-sleep-interval (replaced by core.sleepInterval config file option)
-label-whitelist (replaced by core.labelWhiteList config file option)
-sources (replaced by -label-sources flag)
Introduce two main sections "Deployment" and "Usage" and move "Developer
guide" to the top level, too. In particular, split the huge
deployment-and-usage file into multiple parts under the new main
sections. Move customization guide from "Advanced" to "Usage".
This patch also renames "Advanced" to "Reference" as only that is left
there is reference documentation.
