#57 Makefile should honour --prefix and --exec-prefix

[Mark R. Bannister]

Makefile does not honour --prefix and --exec-prefix options passed to configure script. If they are different locations, the following architecture-independent files are installed under the --exec-prefix location:

pkgbuild
pkgtool
spectool

... while the following architecture-dependent file is installed under the --prefix location:

pkgdbgrep

These files should be installed in their correct locations according to the options passed to the configure script.