ISPN-2580 Do not request segments from all nodes at once

* Split request of transactions and segments into separate methods.
* Transactions and segments are requested serially.
* The segments are requested in a separate thread.

Also fixes "ISPN-2698 Some in-progress segment transfers are not cancelled properly during rehashing".

JIRA: https://issues.jboss.org/browse/ISPN-2580 , https://issues.jboss.org/browse/ISPN-2698