Make JSON files more readable

JSON formatting can be optimized for size or for readability. The JSON
files in openstack-manuals favor readability (for obvious reasons).
Unlike typical JSON formatted for reading (see Wikipedia article on
JSON, or Python's JSON output), however, the files have no space after
the name-separator, making them somewhat harder to read.

This changeset adds the missing space after the name-separator.

It also changes indenting from 3 to 4 spaces (matching our conventions
for Python and shell code).

The order of keys (which doesn't matter for the software parser) has
been preserved, because the order may be intentional (to help human
readers).

For instance:

   "uuid":"d8e02d56-2648-49a3-bf97-6be8f1204f38",

becomes:

    "uuid": "d8e02d56-2648-49a3-bf97-6be8f1204f38",

It also changes a few overly long empty sets. For instance:

   "volume:create":[

   ],

    becomes:

    "volume:create": [],

Change-Id: I559907e72578e6fb1a1a6895bd005ad9b22210d7
Merge "Make JSON files more readable"