ExececutionService could be simplified and documented

[askask]

It has several similar (and apparently unused?) methods, maybe some of them could be removed.

For some methods it's not obvious how to implement them, so it would be nice if there was some documentation.

[dankwart-de]

Could you say which methods you mean? I already simplified things, just give me a hint :)

[askask]

• handleServiceBasedJobExitStatus I don't know what this method is supposed to do? Apparently it still works if I implement it as an empty method, so is it needed?

• ExecutionResult execute(String command, boolean waitForIncompatibleClassChangeError, OutputStream outputStream) and ExecutionResult execute(Command command, boolean waitFor) are unused

• Is it necessary to have execute methods with both command as String and Command; and both with and without waitFor? Those could also be implemented as default methods if required

[dankwart-de]

I did not know how to rename it properly. The method is used to let any software using BE set the job exit stuff like e.g. the job result.

They are not unused in Roddy. We can investigate, if we can reduce the number of methods.

[vinjana]

Maybe we can move all existing execution service classes into RoddyToolLib? (SSHJ, jsch, local)

[askask]

@vinjana I think that might be a good idea.

I also think it's strange that there is a method File queryWorkingDirectory(). First, the value is only used to set the log directory, not he working directory. Second, wouldn't it make more sense to set both the default log directory and default working directory in the job manager?