Clean up configuration documentation

The current format is just copy-paste after auto-conversion and very
inconsistent.  Move discussion of each option into a section and
reword some slightly so they read more clearly.  Group some together
into a section+sub-sections, such as the logging and ip-version option
discussions.

Add a top table-of-contents for the major sections, and then a
separate toc for each of the configuration options that are discussed
in detail.

Change-Id: Iddd27cb54f1d9f062b9c47ff9ad6a2bef3650d6b

Author: ianw