Allow arbitrary formatting of attributes on CLI

[Jiří Stránský]

Currently our formatter for printing resources' attributes can't deal with more complex data, e.g. JSON arrays like `Rack.nodes`. The resulting output on CLI is far from pretty and breaks table formatting. We need a way to format attributes arbitrarily for printing.

Also, we want to have the same formatting algorithms for printing lists and for printing details. In the current codebase (taken from Ceilometer client) they're not very similar.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/43127

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/43127
Committed: http://github.com/stackforge/python-tuskarclient/commit/ca01366beaa75f66d68cc4023691d886f180c086
Submitter: Jenkins
Branch: master

commit ca01366beaa75f66d68cc4023691d886f180c086
Author: Jiri Stransky <email address hidden>
Date: Mon Aug 19 15:48:37 2013 +0200

    Advanced print formatting for CLI

    Modelled mostly after how Heat does it, but with some added power and
    also consistency between print_list and print_dict.

    We have print_list for printing of lists and print_dict for printing
    of show actions. Both functions take as arguments (aside from the data
    to print) also an optional dict of custom formatters (allowing to
    freely format the attributes before printing) and custom labels
    (allowing to tweak table headers and property names). The list is also
    sorted by one of the columns.

    The formatting is showcased on sample formatters and actions -
    rack-show and rack-list.

    Fixes bug 1213056

    Change-Id: Ic14dbb930a5967e2634c1b4777e6705ab2a370ec