Updating to 0.9.0, fixing specfile hardcoded lib path.
Removing 0.8.8 RPATH fix

The 0.8.8 release contained a bad rpath, which required code to
handle (i. e., basically accept) it. Since the 0.9.0 does not
have this bad rpath the checking can be restored to the sane
defaults.
Updating install-spotify.sh and installation package.

Major update. Don't require spec file to be installed, download it instead.
Use set -e instead of home-brewed safe-run. Use rpmdev-setuptree to create
a personal build environment if needed (i. e., so user can build without
root privileges). Only require root privileges to install/uninstall. Use
spotify-make to download .deb packages. Use rpmdev-spectool to download
other sources. Don't hardcode locations to %_srcdir, %_topdir etc.

As a consequence of above, the spec is excluded from the spec file and
the README updated.