Removed *.each calls for nodes other than domains

Paths to type, item, and value nodes were only dependent on obtaining a domain node for each entry, and therefore I replaced the nested structure present before with a single .each loop, only to find each domain node.

The confusion resulted from using syslog provider code as a guideline, as the syslog augeas tree has nested dependencies, but (I believe) the tree for limits.conf should not.
Merge branch 'master' of https://github.com/devynspencer/augeasproviders_limits