Bug 12626: SQLHelper replacement - C4::Acquisition

With this patch, the subroutine NewOrder uses DBIx::Class instead of C4::SQLHelper.

Test plan:
1) Apply the patch

2) Execute the unit tests by launching :
prove t/db_dependent/Acquisition.t

3) The result has to be a success without error or warning :
t/db_dependent/Acquisition.t .. ok
All tests successful.
Files=1, Tests=79,  2 wallclock secs ( 0.04 usr  0.01 sys +  1.80 cusr  0.09 csys =  1.94 CPU)
Result: PASS

4) Log in the koha intranet and create a new order in the acquition module

5) The creation has to be a success

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Bernardo Gonzalez Kriegel <bgkriegel@gmail.com>

Test pass, new order created without problem, no koha-qa errors

Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Tested creating a new order from a subscription, no problems found.
Passes tests and QA script.