perforce: fix checksum

Closes #17841.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
pngcrush 1.7.50

Closes #17834.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
notmuch uses pkg-config

Closes #17833.
siege 2.74

Closes #17842.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>