approach not clear in Intro section

[ivotron]

• [x] Explain better (thoroughly) what a FGRUP is.
• [x] Consider removing Figure 1 to a subsequent section.
• [x] Explain that this is finer granularity with respect to traditional resource utilization quantifications, where we just determine CPU- or memory-bound applications . That is, we don’t mean finer than performance counter, but finer that just CPU- or memory-bound .