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
Nik Everett
Ryan Ernst
andrejserafim