Updated the sysdb submodule to 0.5.0.
Added v0.5.0 release tarballs.
Makefile: Added (commented out) commands for recreating build system.
Updated auto-generated manpages.
Added 0.5.0 release notes.
download/: Added 0.5.0 release.
Linked v0.5.0 release from index page and right panel.
Added 0.5.0 release to news feeds.
Makefile: Call newsconv during install.