move measles test
cleanup measles test
start refactoring stuff out into a base class
refactor condition into base class
move all tests to base class
add birth registration check and tests
Test Mother Received IFA
Merge pull request #4092 from dimagi/opm-es

Test Mother Received IFA
Merge pull request #4091 from dimagi/opm-cz

add birth registration and refactor tests
Make BPR use shared CMR calculations
Merge pull request #4093 from dimagi/opm-es

Make BPR use shared CMR calculations
simplify child weight condition and add tests
Merge pull request #4094 from dimagi/opm-cz

simplify child weight condition and add tests
Merge branch 'master' into opm
remove unused report variable from test utility
change how status and preg_month / child_age are calculated

the main change is updating the window logic to be valid according to
the period that ends N months from the anchor date as per
https://docs.google.com/a/dimagi.com/document/d/1Wu3vZWTbVTYw_oFH10SwgOuY37e7iMyCuHDbyX2zM_E/edit

also includes a fairly sizeable refactor including:
- pull status, preg_month and child_age into properties
- make it clear in the row it is only one month/year
- make datespan calculated from the month/year
- get rid of window entirely
- make end be the first of the next period and update filters to not be inclusive

also updates a subset of tests
fix birth spacing tests based on new window calcs
fix vhnd tests based on the new window calcs
fix preg and child conditions based on new birthspacing calcs
only return vhnd info if the mother meets the right status