add exclude option to check-log
check-ping.rb: Try ping multiple times
memory-metrics: Add dirty memory metric

This is useful for tuning kernel parameters for database applications,
for example.
fix description for --exclude option
Merge pull request #730 from MattMencel/master

Allow mailq path to be set as a config option, defaults to /usr/bin/mail...
Merge pull request #732 from petere/memory-dirty

memory-metrics: Add dirty memory metric
check-ping.rb: Use Integer#times instead
Add ioping-metrics.rb
ioping-metrics.rb: Fix rubocop errors
Merge pull request #731 from maoe/check-ping-multiple-times

check-ping.rb: Try ping multiple times
ioping-metrics.rb: Set executable
Merge pull request #735 from maoe/ioping

Add ioping-metrics.rb
Merge pull request #726 from y13i/add-exclusion-to-check-log

add exclude option to check-log
Fixes doc on one parameter
Merge pull request #736 from pfigue/load-metrics_fix-docs

Fixes doc on one parameter