Add missing MANIFEST.in

Conflicts:
	setup.py
Merge branch 'hotfix/3.1.2'

Conflicts:
	setup.py
Merge branch 'hotfix/next'
Update CHANGELOG.txt
Revert "refactoring widget.visible and IWidgetVisibility"

This reverts commit aa04a584a40decbb6bc8dcac64374797305b3028.
From: LIMS-1395 front page issue tracker url
Merge branch 'develop' into hotfix/next

Conflicts:
	bika/health/browser/analysisrequest/widgets.py
Update CHANGELOG
HEALTH-176 Cannot choose a drug from the dropdown list on Patient->allergies
Version bump 3.1.5
Front page changes
Merge branch 'hotfix/next' v3.1.5

Conflicts:
	CHANGELOG.txt
Merge branch 'master' into develop