Add sections on application-specific profiling and heterogeneous
profiling (i.e. combination of sampling info with info from parallel
programming frameworks).
Note that ARMv8 support is currently being added and tested. (I don't
remove the item as we don't know if it is fully done yet.)
Change NRG_CPU and NRG_GPU to NRG_PP0 and NRG_PP1.
Merge branch 'master' into fnenergy
Fix whitespace.