Test:
  $ ./autogen.sh prefix=/usr && make && sudo make install
  $ ls /usr/share/icons/hicolor/24x24/apps/mate-disk-usage-analyzer.png

TEST on Fedora:
inkscape, librsvg2-tools package are not installed on system: The user can build, install and distribute the package:

  $ sudo dnf remove inkscape librsvg2-tools -y
  $ ./configure --prefix=/usr
  $ make
  $ sudo make install
  $ make distcheck

logview/data/icons:

Can not run build-png-icons target if inkscape package is not installed on system:

  $ make -C logview/data/icons clean-png-icons
make: Entering directory '/home/robert/devel/mate-utils/logview/data/icons'
rm -f hicolor_apps_16x16_mate-system-log.png hicolor_apps_22x22_mate-system-log.png hicolor_apps_32x32_mate-system-log.png hicolor_apps_48x48_mate-system-log.png hicolor_apps_256x256_mate-system-log.png
make: Leaving directory '/home/robert/devel/mate-utils/logview/data/icons'
  $ make -C logview/data/icons build-png-icons
make: Entering directory '/home/robert/devel/mate-utils/logview/data/icons'
make: *** No rule to make target 'hicolor_apps_16x16_mate-system-log.png', needed by 'build-png-icons'.  Stop.
make: Leaving directory '/home/robert/devel/mate-utils/logview/data/icons'

Can run build-png-icons target if inkscape package is installed on system:

  $ sudo dnf install inkscape -y
  $ ./configure --prefix=/usr
  $ make -C logview/data/icons build-png-icons
make: Entering directory '/home/robert/devel/mate-utils/logview/data/icons'
Background RRGGBBAA: ffffff00 Area 303:65:319:81 exported to 16 x 16 pixels (96 dpi) Bitmap saved as: hicolor_apps_16x16_mate-system-log.png
Background RRGGBBAA: ffffff00 Area 303:101:325:123 exported to 22 x 22 pixels (96 dpi) Bitmap saved as: hicolor_apps_22x22_mate-system-log.png
Background RRGGBBAA: ffffff00 Area 304:142:336:174 exported to 32 x 32 pixels (96 dpi) Bitmap saved as: hicolor_apps_32x32_mate-system-log.png
Background RRGGBBAA: ffffff00 Area 296:202:344:250 exported to 48 x 48 pixels (96 dpi) Bitmap saved as: hicolor_apps_48x48_mate-system-log.png
Background RRGGBBAA: ffffff00 Area 33:11:289:267 exported to 256 x 256 pixels (96 dpi) Bitmap saved as: hicolor_apps_256x256_mate-system-log.png
make: Nothing to be done for 'build-png-icons'.
make: Leaving directory '/home/robert/devel/mate-utils/logview/data/icons'

baobab/pixmaps:

Can not run build-png-icons target if librsvg2-tools package is not installed on system:

  $ make -C baobab/pixmaps clean-png-icons
make: Entering directory '/home/robert/devel/mate-utils/baobab/pixmaps'
rm -f hicolor_apps_16x16_mate-disk-usage-analyzer.png hicolor_apps_22x22_mate-disk-usage-analyzer.png hicolor_apps_32x32_mate-disk-usage-analyzer.png hicolor_apps_48x48_mate-disk-usage-analyzer.png hicolor_apps_128x128_mate-disk-usage-analyzer.png
make: Leaving directory '/home/robert/devel/mate-utils/baobab/pixmaps'
  $ make -C baobab/pixmaps build-png-icons
make: Entering directory '/home/robert/devel/mate-utils/baobab/pixmaps'
make: *** No rule to make target 'hicolor_apps_16x16_mate-disk-usage-analyzer.png', needed by 'build-png-icons'.  Stop.
make: Leaving directory '/home/robert/devel/mate-utils/baobab/pixmaps'

Can run build-png-icons target if librsvg2-tools package is installed on system:

  $ sudo dnf install -y librsvg2-tools
  $ ./configure --prefix=/usr
  $ make -C baobab/pixmaps build-png-icons
make: Entering directory '/home/robert/devel/mate-utils/baobab/pixmaps'
/usr/bin/rsvg-convert -w 16 -h 16 hicolor_apps_scalable_mate-disk-usage-analyzer.svg -o hicolor_apps_16x16_mate-disk-usage-analyzer.png
/usr/bin/rsvg-convert -w 22 -h 22 hicolor_apps_scalable_mate-disk-usage-analyzer.svg -o hicolor_apps_22x22_mate-disk-usage-analyzer.png
/usr/bin/rsvg-convert -w 32 -h 32 hicolor_apps_scalable_mate-disk-usage-analyzer.svg -o hicolor_apps_32x32_mate-disk-usage-analyzer.png
/usr/bin/rsvg-convert -w 48 -h 48 hicolor_apps_scalable_mate-disk-usage-analyzer.svg -o hicolor_apps_48x48_mate-disk-usage-analyzer.png
/usr/bin/rsvg-convert -w 128 -h 128 hicolor_apps_scalable_mate-disk-usage-analyzer.svg -o hicolor_apps_128x128_mate-disk-usage-analyzer.png
make: Leaving directory '/home/robert/devel/mate-utils/baobab/pixmaps'

Closes #223

  PNG icons are created if they are not present in icon folder.

  To remove png icons:
    make -C baobab/pixmaps clean-png-icons
    make -C logview/data/icons clean-png-icons

  To build png icons:
    make -C baobab/pixmaps build-png-icons
    make -C logview/data/icons build-png-icons

This removes baobab/pixmaps/shot.png file, use applets-screenshooter
named icon (used in mate-screenshot).