DEVELOPER-916 Re-enable PNG compression
Revert "Merge pull request #461 from pmuir/DEVELOPER-914"

This reverts commit 1fc38833560a6916489355a9e67c7315a47a0dfd, reversing
changes made to 9aae1732e83136bf6822963d0d1abef5e8a69dbb.
Merge pull request #462 from pmuir/DEVELOPER-916

DEVELOPER-916 Re-enable PNG compression