Merge branch 'hotfix-1.8.1'
Merge branch 'release-1.9.0'
bump version 1.9.2
Use contact_link.person #4538

instead of event.participant.person in order to
1) match logic in /people/_contact_row.html.haml partial and;
2) fix issue where event.participant is nil:NilClass
Revert "Use contact_link.person #4538"

This reverts commit 1b545d6e9fa2d91f96458dd36ef665ff8ef55588.
Check that event.participant exists #4538

before calling person on the participant object
Do not show error msg #3313

after marking out of window if the participant
already has pending events.
Do not create duplicate event records #4539

when switching arms we schedule the new event activities.
If the participant already has an event of type, do not create a new
event and cancel the activities in PSC for the newly scheduled segment.
schedule Birth for pregnant lo participant #4536

always - do not check due date against most
recent contact date plus interval. If the participant is pregnant
simply schedule the Birth event next.
Update spec #4539

code behind spec changed.
Merge branch 'hotfix-1.9.2' into develop
Merge branch 'develop' of ssh://github.com/NUBIC/ncs_navigator_core into develop