Add gradle task to stop bluegenes

[danielabutano]

We have a blueGenesStart gralde task but not blueGenesStop

[heralden]

Bluegenes has a stop_web_server_BANG_ function to stop the web server. We could also make the main method take an argument to stop the server.

But I don't think it will be necessary to use these, as killing the process should be enough. I don't know how to do this with gradle/gretty though.

[danielabutano]

When we start bluegenes (from gradle) we call the java main class bluegenes.core; similarly to stop bluegenes we need a java main class.
I have tried
task blueGenesStop(type: JavaExec) { group = 'BlueGenes' classpath = configurations.onlyRunTime main = 'bluegenes.core$stop_web_server_BANG_' }
but it doesn't work.
Decompiling the code, it seems that the java class bluegenes.core$stop_web_server_BANG_ is not a java main class.
This is not urgent.

[danielabutano]

No needed.
The task blueGenesStart is only used to dev purpouses