Currently we use the "gradle project attachment plugin" to support
building elasticsearch as part of another project. However, this plugin
has a number of issues, a large part of which is requiring consistent
use of the projectsPrefix.
This change removes projectsPrefix, and adds support for a special
extra-plugins directory in the root of elasticsearch. Any projects
checked out within this directory will be automatically added to
elasticsearch.
We recently got a run command with gradle, but it is sometimes useful to
run ES with a specific plugin. This is a start, by making each esplugin
have a run command which installs the plugin and runs elasticsearch in
the foreground.
run.sh and run.bat were calling out to the old maven build system.
This is no longer in place, so we've created new gradle tasks to
start an elasticsearch node from the current codebase.
fixed#14423