Removed unused and undocumented gdal_release_date function

try:

    from django.contrib.gis.gdal.driver import Driver

    from django.contrib.gis.gdal.datasource import DataSource

    from django.contrib.gis.gdal.libgdal import gdal_version, gdal_full_version, gdal_release_date, GDAL_VERSION

    from django.contrib.gis.gdal.libgdal import gdal_version, gdal_full_version, GDAL_VERSION

    from django.contrib.gis.gdal.srs import SpatialReference, CoordTransform

    from django.contrib.gis.gdal.geometries import OGRGeometry

    HAS_GDAL = True

    "Returns the full GDAL version information."

    return _version_info('')

def gdal_release_date(date=False):

    """

    Returns the release date in a string format, e.g, "2007/06/27".

    If the date keyword argument is set to True, a Python datetime object

    will be returned instead.

    """

    from datetime import date as date_type

    rel = _version_info('RELEASE_DATE')

    yy, mm, dd = map(int, (rel[0:4], rel[4:6], rel[6:8]))

    d = date_type(yy, mm, dd)

    if date: return d

    else: return d.strftime('%Y/%m/%d')

version_regex = re.compile(r'^(?P<major>\d+)\.(?P<minor>\d+)(\.(?P<subminor>\d+))?')

def gdal_version_info():

    ver = gdal_version().decode()