The list pages' search (filter-table.js) read what was typed as a
regular expression: a "(" or "[" stopped it with an error. It also
needed jQuery, while the instance list had its own script for the same
search. Both are now static/js/table_filter.js: plain text in any case,
the instance list's state list and host groups where a page has them,
remembered for a day as before. A group's header row is marked as one
(data-group-header) instead of being any row without a state.
The list gets a state selector beside the search box. The search now
matches plain text in any case (a '(' no longer breaks it), and in the
grouped list a host's name shows all of its VMs while a host row shows
only while one of its VMs does. The filter moves to
static/js/instance_filter.js with a Node test; the other lists keep
filter-table.js. Collapsing a host now sets a class on its table body
instead of each row's display, so a collapsed host and the filter no
longer undo each other.