When uniquifying properties, also sort them on the owning package.
This ensures that whenever two packages provide or (or require, obsolete
or conflict) the same property, they appear in the same order in the
propertys list of packages.
2 exec_prefix=@exec_prefix@
4 includedir=@includedir@
7 Description: library for depsolving, installing and removing packages
10 Libs: -L${libdir} -lexpat -lz -lcurl
11 Cflags: -I${includedir}/razor