1. reduce the number of cmake warnings
2. remove unused OLD policies
3. only warn about missing prerequisites once
4. start cmake output from columnstore version
Rename packages to MariaDB-columnstore-engine, MariaDB-columnstore-libs
and MariaDB-columnstore-platform.
Also add the "columnstore-" prefix the the components so that MariaDB's
packaging system understands then and add a line to include them in
MariaDB's packaging.
In addition
* Fix S3 building for dist source build
* Fix Debian 10 dependency issue
* Fix git handling for dist builds
* Add support for MariaDB's RPM building
* Use MariaDB's PCRE and readline
* Removes a few dead files
* Fix Boost noncopyable includes
cpimport now has the ability to use libmarias3 to read an object from an
S3 bucket instead of a file on local disk.
This also moves libmarias3 to utils/libmarias3.