testnode: scalability test runner update

- hardcoded software release url removed (http with password protection for now)
- scalability runner handles frontend request. It asks for a local master frontend apache software installation and instance request.
- testsuite brings the urls corresponding to instance, bootstrap, metrics collection.
- vinculation between scalability runner and runScalability script. Process manager is used to run the script as a command.
- scalability runner manages the test result cases and loops among different testsuite configurations.
- userhosts software is used to run the command for the runScalability script, to solve DNS.
- refactoring according to last changes in TaskDistribution
- general refactoring and cleanup