#446 Deceased validation code

[Scott W.]

https://github.com/openemr/openemr/commit/ce339787805777665994b80e880a807177fc88cc

The added code in the commit above needs to check to make sure that:

1) Deceased item exists in layout
2) It is not unused. (LBF Layout)

If 'form_deceased_date' is set as unused or deleted, patients can't be added or edited.