Redesign the tutorial #1158
Description
The current tutorial assumes that you have already set up ReFrame for a cluster. Although configuration is generally easy, it makes the tutorial specific to the system that it was designed for and, therefore, not as much generic as we would like it to be, so that users can immediately start experiencing with ReFrame.
The tutorial should really start with the generic system, exactly as ReFrame is downloaded. It should present all the general concepts for writing a test and the basic command line options. Subsequent examples should build on to of that by enhancing the configuration and adding more complex tests. Last step would be to configure ReFrame for an HPC system and show how the same tests can be ported there.
The tutorial should not serve the purpose of explaining the details of the configuration or of other aspects of the framework. These should be addressed in all the details in dedicated sections. See also #1157.