[1.6.x] Updated a bunch of hyperlinks in documentation

Backport of 626bdf648 from master.

docs/ref/contrib/gis/admin.txt

@@ -67,6 +67,6 @@ GeoDjango's admin site
 .. class:: OSMGeoAdmin
 
    A subclass of :class:`GeoModelAdmin` that uses a spherical mercator projection
-   with `OpenStreetMap <http://openstreetmap.org/>`_ street data tiles.
+   with `OpenStreetMap <http://www.openstreetmap.org/>`_ street data tiles.
    See the :ref:`OSMGeoAdmin introduction <osmgeoadmin-intro>`
    in the tutorial for a usage example.

docs/ref/contrib/gis/feeds.txt

@@ -13,7 +13,7 @@ Django's, please consult :doc:`Django's syndication documentation
 
 .. _W3C Geo: http://www.w3.org/2003/01/geo/
 
-__ http://georss.org/1.0#simple
+__ http://georss.org/simple.html
 
 Example
 =======

docs/ref/contrib/gis/forms-api.txt

@@ -14,7 +14,7 @@ display and edit geolocalized data on a map. By default, they use
 `OpenLayers`_-powered maps, with a base WMS layer provided by `Metacarta`_.
 
 .. _OpenLayers: http://openlayers.org/
-.. _Metacarta: http://metacarta.com/
+.. _Metacarta: http://www.metacarta.com/
 
 Field arguments
 ===============

docs/ref/contrib/gis/install/index.txt

@@ -140,7 +140,7 @@ community!  You can:
   sure to provide a complete description of the problem, versions used,
   and specify the component as "GIS".
 
-__ http://groups.google.com/group/geodjango
+__ https://groups.google.com/d/forum/geodjango
 __ https://code.djangoproject.com/newticket
 
 .. _libsettings:
@@ -272,7 +272,7 @@ Summary::
     $ brew install gdal
     $ brew install libgeoip
 
-__ http://mxcl.github.com/homebrew/
+__ http://brew.sh/
 .. _Apple Developer Tools: https://developer.apple.com/technologies/tools/
 
 .. _kyngchaos:

docs/ref/contrib/gis/install/postgis.txt

@@ -15,7 +15,7 @@ might also need additional libraries, see `PostGIS requirements`_.
     when using GeoDjango with PostGIS.
 
 .. _psycopg2: http://initd.org/psycopg/
-.. _PostGIS requirements: http://www.postgis.org/documentation/manual-2.0/postgis_installation.html#id2711662
+.. _PostGIS requirements: http://www.postgis.org/documentation/manual-2.0/postgis_installation.html#id554707
 
 On Debian/Ubuntu, you are advised to install the following packages:
 postgresql-x.x, postgresql-x.x-postgis, postgresql-server-dev-x.x,

docs/ref/contrib/gis/measure.txt

@@ -175,6 +175,6 @@ Measurement API
    Alias for :class:`Area` class.
 
 .. rubric:: Footnotes
-.. [#] `Robert Coup <http://koordinates.com/>`_ is the initial author of the measure objects,
+.. [#] `Robert Coup <https://koordinates.com/>`_ is the initial author of the measure objects,
        and was inspired by Brian Beck's work in `geopy <http://code.google.com/p/geopy/>`_
        and Geoff Biggs' PhD work on dimensioned units for robotics.

docs/ref/contrib/gis/sitemaps.txt

@@ -23,4 +23,4 @@ Reference
 -----------------
 
 .. rubric:: Footnotes
-.. [#] Google, Inc., `What is a Geo Sitemap? <http://support.google.com/webmasters/bin/answer.py?answer=94555>`_.
+.. [#] Google, Inc., `What is a Geo Sitemap? <https://support.google.com/webmasters/answer/94555>`_.

docs/ref/contrib/gis/tutorial.txt

@@ -747,7 +747,7 @@ entries -- the borders may be edited by clicking on a polygon and dragging
 the vertexes to the desired position.
 
 .. _OpenLayers: http://openlayers.org/
-.. _Open Street Map: http://openstreetmap.org/
+.. _Open Street Map: http://www.openstreetmap.org/
 .. _Vector Map Level 0: http://earth-info.nga.mil/publications/vmap0.html
 .. _OSGeo: http://www.osgeo.org