This works on Linux and on Windows, with rpm/deb/tar.gz/zip
installations.
For rpm/deb it just works, for tar.gz/zip there is no
standard location, so one needs to configure plugin with
-DCMAKE_PREFIX_PATH=/pah/to/mariadb/basedir
after that, `cmake --install .` works too, installing in the same
basedir.
`cmake --build . --target package` works, creating rpm/deb/targz/zip
depending on whether it's Linux or Windows and whether -DRPM or -DDEB
was specified.
* create and install mariadb-plugin-config.cmake
* for now it only supports one plugin per project, error out
if there are many
* deb: move all headers that plugins need to libmariadb-dev,
together with libmysqlservices.a. At least until we'll
create mariadb-plugin-dev. Nobody should need huge
libmariadbd-dev to develop a plugin
* rpm: all in MariaDB-devel already, no changes here
* install wsrep headers too, THD layout depends on WITH_WSREP
* show DBUG_OFF, ENABLED_DEBUG_SYNC, and SAFE_MUTEX to plugins, same
reason (it doesn't happen automatically as they're not in my_config.h)
* but don't install config.h - high chance of name conflict with other
projects and it's an exact copy of my_config.h anyway.
* adjust plugin.cmake to work for external plugins
* move server-internal part of it to top-level CMakeLists.txt
* remove double-defined macros from unireg.h (the guard doesn't help
if unireg.h is included first)
* package plugin metadata as yaml in .tar.gz/.zip
ColumnStore, until fixed, needs a backward-compatibility workaround
3977a282b7