Deprecate timeout attribute/function

Keep only `httpTimeout` and `transactionTimeout` to be configurable by the user of the client.

Deprecate the `timeout` parameter, and if present use it only for the `httpTimeout` if it's not define.
=> Do not try to guess/compute a Nuxeo transaction timeout based on that.

Document that:

• the `httpTimeout` is in ms, and work only in a Node.js context
• the `transactionTimeout is in seconds