clean up fadvise use on WritableFile.  clean up foreground/background selection of operations in PosixMmapFile.
correct syntax errors hidden on Mac OSX
prepare in-active code at key spots while looking around
Reverse the pattern.  Default is same thread like .sst.  Setup recovery log and others to use background.
explicitly put recovery log into background write/close loop
Clear gcc variable not used warning, but keep call to h->key() incase the call creates side effects.
Add fallback error reporting to syslog and to new perf_counter.  Enable SetForCompaction() in this code base (though not for an already open file).
Update comments per code review.
update comments and whitespace issues per code review.
Merge pull request #88 from basho/mv-sst-fadvise

Mv sst fadvise