Bug 17646: Remove itemtype-related IssueSlip.t warnings

Bug 17646: Remove itemtype-related IssueSlip.t warnings

This patch makes t/db_dependent/Members/IssueSlip.t create
good sample data for its tests. It does so by creating a random
itemtype.

To test:
- Run
  $ prove t/db_dependent/Members/IssueSlip.t
=> FAIL: lots of warnings about "item-level_itypes set but no itemtype
set for item"
- Apply the patch
- Run:
  $ prove t/db_dependent/Members/IssueSlip.t
=> SUCCESS: Tests are green, and no warnings.
- Sign off :-D

Sponsored-by: ByWater Solutions
Signed-off-by: Hector Castro <hector.hecaxmmx@gmail.com>
All test pass successfuly

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Mason James <mtj@kohaaloha.com>