qa_tests/hazard/disagg/case_1/test:

Updated expected test values. Bear in the mind that this test is currently
just for stability; the results were not independently computed.
calcs/hazard/disaggregation/core:

Use the new `disaggregation_poissonian` calc function.
qa_tests/hazard/disagg/case_1:

Added a 'hazard' nose attribute to this test case.
qa_tests/hazard/disagg/case_1/test:

Added a custom XML test method which has slightly relaxed precision when
comparing probability values.

The reason for this change is that there seem to be very minor differences
in these values, depending on the platform and environment.
Merge pull request #1044 from larsbutler/new-disagg-equation

Update to disaggregation equation

[r=matley] [f=1116262]