REM3-196 - user proper values to initialize rec/send buffers + fix leak debug

JIRA: https://issues.jboss.org/browse/REM3-196


PRs:
Master: https://github.com/jboss-remoting/jboss-remoting/pull/26
3.x: https://github.com/jboss-remoting/jboss-remoting/pull/27