*8958* Cleanup unset/unused variables in usageStats plugin settings form.
Remove orphaned COUNTER locale files
Update comments for plugins/generic/counter to plugins/reports/counter
Merge pull request #339 from ulsdevteam/cleanup-orphaned-counter-locales

Cleanup COUNTER plugin move from generic to reports
Merge pull request #329 from ulsdevteam/cleanup-usageStatus-form-variables

*8958* Cleanup unset/unused variables in usageStats plugin settings form
Merge remote-tracking branch 'upstream/ojs-dev-2_4' into ojs-dev-2_4