feature #2371: add pagination to ruby oca, cli and sunstone

There is a new pool method called get_hash that uses pagination when possible.

The default page size can be changed with the environment variable
ONE_POOL_PAGE_SIZE. Any value > 2 will set a page size, a non
numeric value disables pagination.

Paginated pools are parsed using sax instead of dom so this makes the parse
a bit faster. It will also detect Ox gem (https://github.com/ohler55/ox) and
will use it as it is much faster than Nokogiri.

Screen cleaning in top command is done after retrieving the pool reducing
the flickering.