Geoa contrib module using Geoalchemy2 elements with SRID support

fix pull request #729 python 3 compatibility

Add test for single custom filter on relation and column_labels

Conflicts:
	doc/db_geoa.rst

Up to date

Commented out section that doesn't seem to match how leaflet returns deleted values. Allowed for formating differences in another geojson string.

Clarify docs re: geoa ModelView

Probably doing something horrible! Using current_app.extensions['sqlalchemy'].db.session to get a valid session for getting the list view maps into the correct SRID

Changes to use Geoalchemy2/PostGIS functions. Doesn't currently work as it requires access to the db.session.

Optimize applyGlobalStyles - issue #721

Fix mongoengine `ListField(EmbeddedDocumentField('Model'))`

to `Model` and raising `TypeError: 'str' object is not callable`

Fix active filters when named_filter_urls=True

Use col-md to match rest of form on mobile devices

fix "In List" integer/float filter validation

fix mongoengine and peewee exceptions when filtering for non-integer values