Updating docs regarding pulling in and fetching git submodules

We use this for PDF.js now... we should reference that.

This commit sponsored by Bonnie King.  Thanks!

docs/source/siteadmin/deploying.rst

@@ -157,9 +157,10 @@ directory. Modify these commands to reflect your own environment::
     mkdir -p /srv/mediagoblin.example.org/
     cd /srv/mediagoblin.example.org/
 
-Clone the MediaGoblin repository::
+Clone the MediaGoblin repository and set up the git submodules::
 
     git clone git://gitorious.org/mediagoblin/mediagoblin.git
+    git submodule init && git submodule fetch
 
 And set up the in-package virtualenv::
 
@@ -194,7 +195,7 @@ This concludes the initial configuration of the development
 environment. In the future, when you update your
 codebase, you should also run::
 
-    ./bin/python setup.py develop --upgrade && ./bin/gmg dbupdate
+    ./bin/python setup.py develop --upgrade && ./bin/gmg dbupdate && git submodule fetch
 
 Note: If you are running an active site, depending on your server
 configuration, you may need to stop it first or the dbupdate command

docs/source/siteadmin/relnotes.rst

@@ -31,6 +31,8 @@ fix in the newly released document support which prevented the
 If you were running 0.4.0 you can upgrade to v0.4.1 via a simple
 switch and restarting mediagoblin/celery with no other actions.
 
+Otherwise, follow 0.4.0 instructions.
+
 
 0.4.0
 =====
@@ -56,6 +58,9 @@ switch and restarting mediagoblin/celery with no other actions.
 5. We now use itsdangerous for sessions; if you had any references to
    beaker in your paste config you can remove them.  Again, see the
    default paste.ini config
+6. We also now use git submodules.  Please do:
+   ``git submodule init && git submodule fetch``
+   You will need to do this to use the new PDF support.
 
 **For theme authors**