New version 1.9.0

Most of the new release consists of a new test-tool based on the
CUnit framework:  iscsi-test-cu
The old test-tool iscsi-test remains as-is for legacy use but will not be
expanded with any new tests.

Other changes include
 - Add tests for persistent reservations.
 - Autotool updates and bugfixes
 - Add pkgconfig file