linux: Add support for zram
rxvt-unicode: add 256-color resources patch
Enable encrypted backing devices in fileystem configurations
ssh: Support knownHost public keys as strings
sshd: Fix typing for options which take paths
hplip version bump 3.11.1 -> 3.14.4
hplip: add binary plugin
hplip: assume maintainership
hplip: add pillow and reportlab dependencies
sane: add mkSaneConfig
hplip: avoid name collision with sane config files
sane: use mkSaneConfig to set system environment
mupdf: build with -fpic
mupdf: build a shared library instead
openjpeg: provide .pc
zathura: mupdf plugin
hplip: don't use udev rules to change device owner
Add unicode3 option to rxvt_unicode

Needed to user fonts patched for powerline.
Fix passing extra qemu opts when using boot loader
Add gvfs dbus service and gvfs gio modules to gnome 3

Closes #2746