Move reports pruning into the Node model, move report bulk delete into the Report model.

This is significantly faster than having either ActiveRecord or the
database do the cascading report deletion, while the database still
maintains the FK integrity when bulk delete the transaction commits.
Progress bar for reports:prune
Show variables in sorted order
Wider forms with wider variables key field
Add form .element padding-right: 20% to match the sidebar width
Begin to use the parameter_input partial for inventory search. Almost working.
Refactor the parameter input partial.

This removes an intermediary hash, since we were right away doing
hash.values and dropping the keys. The form element names are now
configurable, with reasonable defaults.
Merge remote-tracking branch 'origin/rails3-wideforms'
Merge branch 'rails3-reports-prune-destroy'
Merge remote-tracking branch 'origin/rails3-invsearch'