Add support for strptime-converted search terms
Add support for strptime-converted search terms

Searching for strings like "january" or "dec" will discover date
columns with values matching ``__year=1`` and ``__year=12``,
respectively.  There is probably room to improve this (and weekday
names are complex enough that they're omitted from this initial
support) but this is a pretty big step in the right direction.

addgene/django-datatable-view,annaproch/django-datatable-view,jangeador/django-datatable-view,annaproch/django-datatable-view,doganmeh/django-datatable-view,pivotal-energy-solutions/django-datatable-view,pivotal-energy-solutions/django-datatable-view,greenbender/django-datatable-view,addgene/django-datatable-view,doganmeh/django-datatable-view,jangeador/django-datatable-view,doganmeh/django-datatable-view,greenbender/django-datatable-view,annaproch/django-datatable-view,greenbender/django-datatable-view,addgene/django-datatable-view,pivotal-energy-solutions/django-datatable-view,jangeador/django-datatable-view