Added "Clear" button to datatable search field
Added "Clear" button to datatable search field

Since the table state is preserved between navigation actions, having a
simple clear button goes a long way for usability.

greenbender/django-datatable-view,RamezIssac/django-datatable-view,greenbender/django-datatable-view,greenbender/django-datatable-view,addgene/django-datatable-view,jangeador/django-datatable-view,RamezIssac/django-datatable-view,jangeador/django-datatable-view,CloudNcodeInc/django-datatable-view,annabed/django-datatable-view,doganmeh/django-datatable-view,johnrtipton/django-datatable-view,annaproch/django-datatable-view,addgene/django-datatable-view,RamezIssac/django-datatable-view,annaproch/django-datatable-view,pivotal-energy-solutions/django-datatable-view,jangeador/django-datatable-view,CloudNcodeInc/django-datatable-view,pivotal-energy-solutions/django-datatable-view,doganmeh/django-datatable-view,johnrtipton/django-datatable-view,CloudNcodeInc/django-datatable-view,johnrtipton/django-datatable-view,doganmeh/django-datatable-view,addgene/django-datatable-view,annaproch/django-datatable-view,annabed/django-datatable-view,annabed/django-datatable-view,pivotal-energy-solutions/django-datatable-view