Hello,

as there has been a new stable release in the meantime, I updated to this.
I also simplified the package a bit, maybe due to the new release one
substitute did not apply any more, another one did not seem to be necessary
regardless, and several "substitute*" on the same file can be combined into
one expression. I then set PREFIX and used it in a substitution, which
makes some CFLAGS unnecessary, and others are there by default in the
current Makefile. Finally I made the description a bit more neutral.

The resulting calc binary seems to work, if you are happy with the
package, I could push it.

Andreas