Add skipped_repairs stat.
lager message on stat_update_error changed from error to debug.

add skipped_read_repairs to legacy stat map
Merge pull request #1050 from basho/uw-add-skipped-repairs-stat

Add skipped_repairs stat.

Reviewed-by: jburwell
Remove afunix from EXOMETER_PACKAGES.
Afunix is not used at this time, and may cause build issues on some
platforms.