tree de8eafd6a8c372f3bdb70a51ed799896bdc99c30
parent 58eedced2578c143705c1d8503e4ed3a40aaa8b3
author Cosmin Truta <ctruta@gmail.com> 1534640462 -0400
committer Cosmin Truta <ctruta@gmail.com> 1534640462 -0400

Replace the remaining uses of PNG_CONST with const

In v1.6.0, compiler support for const became a requirement.
It should be used consistently. To maintain backwards compatibility,
PNG_CONST is still maintained in deprecated form.