fixed a few broken license declarations. should have been BSD not GPL

--HG--
branch : trunk
diff --git a/jinja2/compiler.py b/jinja2/compiler.py
index 2d96d0d..f1e182b 100644
--- a/jinja2/compiler.py
+++ b/jinja2/compiler.py
@@ -6,7 +6,7 @@
     Compiles nodes into python code.
 
     :copyright: Copyright 2008 by Armin Ronacher.
-    :license: GNU GPL.
+    :license: BSD.
 """
 from copy import copy
 from keyword import iskeyword
diff --git a/jinja2/optimizer.py b/jinja2/optimizer.py
index 4838971..43065df 100644
--- a/jinja2/optimizer.py
+++ b/jinja2/optimizer.py
@@ -14,7 +14,7 @@
     The solution would be a second syntax tree that has the scoping rules stored.
 
     :copyright: Copyright 2008 by Christoph Hack, Armin Ronacher.
-    :license: GNU GPL.
+    :license: BSD.
 """
 from jinja2 import nodes
 from jinja2.visitor import NodeTransformer
diff --git a/jinja2/runtime.py b/jinja2/runtime.py
index d6c5553..496b484 100644
--- a/jinja2/runtime.py
+++ b/jinja2/runtime.py
@@ -6,7 +6,7 @@
     Runtime helpers.
 
     :copyright: Copyright 2008 by Armin Ronacher.
-    :license: GNU GPL.
+    :license: BSD.
 """
 import sys
 from types import FunctionType, MethodType
diff --git a/jinja2/visitor.py b/jinja2/visitor.py
index 8c94803..ad11108 100644
--- a/jinja2/visitor.py
+++ b/jinja2/visitor.py
@@ -6,7 +6,7 @@
     This module implements a visitor for the nodes.
 
     :copyright: Copyright 2008 by Armin Ronacher.
-    :license: GNU GPL.
+    :license: BSD.
 """
 from jinja2.nodes import Node