Add Netpbm messages to verbose output

Add Netpbm messages to verbose output

Messages of Netpbm commands
(pngtopnm, pnmscale, pnmtopng)
output to /dev/null.
So those messages couldn't be read.

This patch can add them to verbose output,
and they can be read.

[pkx166h, 2015-05-31 10:59:45]

Patch counted down - please push

[trueroad, 2015-05-31 13:51:20]

I've pushed.

Issue 4420: Add Netpbm messages to verbose output

author    Masamichi Hosoda <trueroad@trueroad.jp>
          Mon, 25 May 2015 14:41:16 +0000 (23:41 +0900)
committer Masamichi Hosoda <trueroad@trueroad.jp>
          Sun, 31 May 2015 13:39:19 +0000 (22:39 +0900)
commit    b666e5959e3eb170e57bb1937f9589cfbe7c0ae4