viewnior: Update to 1.7

Viewnior 1.7
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New features included:
- Show image dimensions to title bar
- Add option to hide the scrollbars
- Wallpaper support for Cinnamon, Puppylinux, and autodetect DE
- Updated translations

Fixed:
- Setting wallpaper on XFCE 4.12+ and MATE

Misc:
- Move to the Meson Build system

Viewnior 1.6
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New features included:
- Support back & forward buttons on your mouse

Fixed:
- Mouse scroll behaviour and actions settings

Viewnior 1.5
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New features included:
- Disable Wallpaper support during compilation
- Updated translations

Fixed:
- Preferences menu position
- Nitrogen wallpaper support

Viewnior 1.4
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New features included:
- Read EXIF and IPTC metadata
- Nitrogen support
- Updated translations

Fixed:
- Preserve metadata after image modification
- Rendidering artifacts when panning

(nia)