This patch adds exception logging to the swift service API. Each
operation that results in failure of any operation will now log
the exception as well as report a timestamp and full stack trace
in the results returned by the service API calls.

Change-Id: I7336b28354e7740ea7d048bdf355e3c1a1b4436c

The current code builds a full object listing before performing either a multiple
download or delete operation (and also shuffles this complete list in the case of
a download). This patch removes the creation of the full object list and adds the
ability to turn off shuffle for files when downloading. Also added is a limit on
the number of list results that can be queued by a single call to service.list
without consuming results (reduces memory overhead for large listings).

Some tests added for service.py download and list.

Change-Id: Ie737cbb7f8b1fa8a79bbb88914730b05aa7f2906

This patch adds "--output-dir" and "--remove-prefix" options
to the "download" command and unit tests for it.

Example:

    $ swift list example --prefix swift2.2
    swift2.2/bin/swift-object-auditor
    swift2.2/bin/swift-object-expirer
    swift2.2/bin/swift-object-info
    swift2.2/bin/swift-object-replicator
    swift2.2/bin/swift-object-server
    swift2.2/bin/swift-object-updater

When given "--output-dir <directory>", client downloads objects to <directory>.

    $ swift download example --prefix swift2.2 \
                    --output-dir new/swift/dir

    The folder structure:
    .
    └── new
        └── swift
            └── dir
                └── swift2.2
                    └── bin
                        ├── swift-object-auditor
                        ├── swift-object-expirer
                        ├── swift-object-info
                        ├── swift-object-replicator
                        ├── swift-object-server
                        └── swift-object-updater

When given "--remove-prefix", client downloads objects without <prefix>.

    $ swift download example --prefix swift2.2 \
                    --remove-prefix \
                    --output-dir swift

    The folder structure:
    .
    └── swift
        └── bin
            ├── swift-object-auditor
            ├── swift-object-expirer
            ├── swift-object-info
            ├── swift-object-replicator
            ├── swift-object-server
            └── swift-object-updater

Co-Authored-By: Clay Gerrard <clay.gerrard@gmail.com>
Change-Id: I7463fe2941cc94f9a50a4756a97c2ccdf946294d
Implements: blueprint swiftclient-download-pseudo-folder-to-specific-target

The option from argparse in shell is 'header' and that is what is used
in the code.

Change-Id: I5c889192ef7c46c299dc0ec7cbc7c4d027dae6d5

Currently SwiftClient populate response dictionary before
removing "./" or "/" at begining of object name. This patch
fixes that by changing that order.

Closes-bug: #1412425
Change-Id: I80222754caba5d42a468f4677ac539e46682dd31

This allows the use of --skip-identical when downloading SLOs and DLOs,
while still only requiring one request for normal objects.

Change-Id: I237ec5a8cc4d1119b6d3f166db81a977a50a4e4e
Related-Bug: #1379252

In addition to removing an unnecessary dependency, this closes another
hole that was allowing raw bytes to appear in user-facing messages.

Change-Id: Ia0b76426a38e5a5c368c4c7e7ba2aef286758aca