Add etcd support with self and store metrics.
Don't create unnecessary tags var
Roll up the big lists of names into class vars.
First pass at agent check stuff.
Remove version check stuff.
Don't use a magic number for the default timeout.
Remove default timeout and document the instance variable.
Fix it up to work.
Integrated improvements from Leo
Stop mixing format and % params Cory!
Fix tags.
Merge pull request #1235 from gphat/add-etcd-check

Add etcd support with self and store metrics.