pkg/52936: mupdf pkg requires zlib v1.2.3

[rustydev7%gmail.com@localhost]

>Number:         52936
>Category:       pkg
>Synopsis:       mupdf pkg requires zlib v1.2.3
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Jan 21 03:00:00 +0000 2018
>Originator:     Rusty Dev
>Release:        7.1.1
>Organization:
>Environment:
NetBSD 7.1.1 NetBSD 7.1.1 (Generic.201712222334Z) amd64
>Description:
mupdf fails to build with z_const undefined. It requires zlib v1.2.3 as a dependency. 
>How-To-Repeat:
cd /usr/pkgsrc/print/mupdf && make
>Fix:
add 
BUILDLINK+= zlib>=1.2.3
to buildlink3.mk