whatami: update for Fedora (vs. Fedora Core)

Adrian Reber points out that Fedora Core hasn't existed for a long
time.  But instead of deleting that block, be conservative: add
another block for "Fedora ".
whatami: update for newer Apple hardware

Also recognize "Intel Core i<digit>" in the OS X system_profiler
output.
functions: add next_pwr2() and calc_free_memory(percentage,cores)
mtt: add test_ini_param to fetch arbitrary value for test key
Merge branch 'master' of https://github.com/open-mpi/mtt