Contact API on-demand, describe only one version

It is not necessary to ask description of all versions,
instead, ask for only selected version or the default one.
Object-like access to resources.

When an action returns layout object or object_list,
ResourceInstance objects are created, which defines attributes
and methods representing the resource.
Implement action name aliases

Alias 'new' is always ignored, as it is used by the client
to create new resource-object instances.
Description in an envelope
Cli: show examples from the API in -h, fix communication

Fixes communication with the API whose protocol has changed.
Depends on table_print 1.5.3 because of tp.set :io availability.
Cli: add --version, --client-version, update readme

Option --version selects API version to use, --client-version
prints the client version and exits.