Improved test invokation. Picks up doctests within Jinja now, changed
doctests that just show usage that would not work on their own so that
they are standard code blocks now and do not disturb testing.

--HG--
branch : trunk
diff --git a/jinja2/loaders.py b/jinja2/loaders.py
index 5d5723d..7dda2ae 100644
--- a/jinja2/loaders.py
+++ b/jinja2/loaders.py
@@ -164,9 +164,9 @@
 class PackageLoader(BaseLoader):
     """Load templates from python eggs or packages.  It is constructed with
     the name of the python package and the path to the templates in that
-    package:
+    package::
 
-    >>> loader = PackageLoader('mypackage', 'views')
+        loader = PackageLoader('mypackage', 'views')
 
     If the package path is not given, ``'templates'`` is assumed.
 
@@ -233,7 +233,7 @@
     filename, uptodatefunc)`` or `None` if the template does not exist.
 
     >>> def load_template(name):
-    ...     if name == 'index.html'
+    ...     if name == 'index.html':
     ...         return '...'
     ...
     >>> loader = FunctionLoader(load_template)
@@ -260,12 +260,12 @@
     """A loader that is passed a dict of loaders where each loader is bound
     to a prefix.  The prefix is delimited from the template by a slash per
     default, which can be changed by setting the `delimiter` argument to
-    something else.
+    something else::
 
-    >>> loader = PrefixLoader({
-    ...     'app1':     PackageLoader('mypackage.app1'),
-    ...     'app2':     PackageLoader('mypackage.app2')
-    ... })
+        loader = PrefixLoader({
+            'app1':     PackageLoader('mypackage.app1'),
+            'app2':     PackageLoader('mypackage.app2')
+        })
 
     By loading ``'app1/index.html'`` the file from the app1 package is loaded,
     by loading ``'app2/index.html'`` the file from the second.
@@ -291,7 +291,7 @@
 
     >>> loader = ChoiceLoader([
     ...     FileSystemLoader('/path/to/user/templates'),
-    ...     PackageLoader('mypackage')
+    ...     FileSystemLoader('/path/to/system/templates')
     ... ])
 
     This is useful if you want to allow users to override builtin templates