Instead of lengthy blurbs, switch to single-line, machine-readable
standardized (https://spdx.dev) license identifiers. The Linux kernel
switched long ago, so there is strong precedent.
Three cases are handled: AGPL-only, Apache-only, and dual licensed.
For the latter case, I chose (AGPL-3.0-or-later and Apache-2.0),
reasoning that our changes are extensive enough to apply our license.
The changes we applied mechanically with a script, except to
licenses/README.md.
Closes#9937
We used to use /opt/scylladb just for Scylla build toolchain and
dependency libraries, not for Scylla main package.
But since we merged relocatable package, Scylla main binary and
dependency libraries are all located under /opt/scylladb, only
setup scripts remained on /usr/lib/scylla.
It strange to keep using both /usr/lib/<app name> and /opt/<app name>,
we should merge them into single place.
Message-Id: <20190614011038.17827-1-syuu@scylladb.com>
