Bug 14699: Reword "Select all/Clear all" and change their behaviour

Bug 14699: Reword "Select all/Clear all" and change their behaviour

"Select all" -> "Select all visible rows"
"Clear all" -> "Clear selection on visible rows"

+ fix the bug where the Delete link was visually enabled only if you
checked a box in the first page (now every checkbox enable the link)

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>