Use glyphicon sep between filter name and value

Separator is added in CSS. Previously a unicode "heavy right-pointing
angle quotation mark ornament", but Windows Chrome and iOS Safari
were having trouble displaying that. Instead, use glphyicon
right chevron, at 70% size for reasonable display.
Merge pull request #932 from projectblacklight/new_filter_name_separator

Use glyphicon sep between filter name and value