Fixes #248 - Generalise tab management and search facility

The search facility is now available from all controllers.
The search bar is only displayed if there is a partial
<controller_name>/_search_line.html.erb available.This partial also
describes and implements the possible search parameters for this controller...

Fixes #183 - Adds searchbar facility to hosts

Qualified the fact_selected partial
Added a reset button
Added popup help
Beautification and grooming