Changed name from "fork" to "insertion_point" (codewriter), introduced func context

Cython/Compiler/Annotate.py

@@ -25,7 +25,7 @@ class AnnotationCCodeWriter(CCodeWriter):
             self.last_pos = None
             self.code = {}
         else:
-            # When forking, keep references to the same database
+            # When creating an insertion point, keep references to the same database
             self.annotation_buffer = create_from.annotation_buffer
             self.annotations = create_from.annotations
             self.code = create_from.code

Cython/Compiler/ModuleNode.py

@@ -239,7 +239,7 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
             code = Annotate.AnnotationCCodeWriter()
         else:
             code = Code.CCodeWriter()
-        h_code = code.fork()
+        h_code = code.insertion_point()
         self.generate_module_preamble(env, modules, h_code)
 
         code.putln("")

Cython/StringIOTree.py

@@ -24,7 +24,7 @@ class StringIOTree(object):
     def write(self, what):
         self.stream.write(what)
 
-    def fork(self):
+    def insertion_point(self):
         # Save what we have written until now
         # (would it be more efficient to check with len(self.stream.getvalue())?
         # leaving it out for now)
@@ -36,30 +36,29 @@ class StringIOTree(object):
         return other
 
 __doc__ = r"""
-Implements a forkable buffer. When you know you need to "get back" to a place
-and write more later, simply call fork() at that spot and get a new
-StringIOTree object that is "left behind", *behind* the object that is
-forked.
+Implements a buffer with insertion points. When you know you need to
+"get back" to a place and write more later, simply call insertion_point()
+at that spot and get a new StringIOTree object that is "left behind".
 
 EXAMPLE:
 
->>> pyrex = StringIOTree()
->>> pyrex.write('first\n')
->>> cython = pyrex.fork()
->>> pyrex.write('third\n')
->>> cython.write('second\n')
->>> print pyrex.getvalue()
+>>> a = StringIOTree()
+>>> a.write('first\n')
+>>> b = a.insertion_point()
+>>> a.write('third\n')
+>>> b.write('second\n')
+>>> print a.getvalue()
 first
 second
 third
 <BLANKLINE>
 
->>> b = cython.fork()
->>> a = b.fork()
->>> a.write('alpha\n')
->>> cython.write('gamma\n')
->>> b.write('beta\n')
->>> print cython.getvalue()
+>>> c = b.insertion_point()
+>>> d = c.insertion_point()
+>>> d.write('alpha\n')
+>>> b.write('gamma\n')
+>>> c.write('beta\n')
+>>> print b.getvalue()
 second
 alpha
 beta
@@ -67,7 +66,7 @@ gamma
 <BLANKLINE>
 
 >>> out = StringIO()
->>> pyrex.copyto(out)
+>>> a.copyto(out)
 >>> print out.getvalue()
 first
 second