Updates for building and bundling with Python3

Note that building currently requires bouncing back and forth between python2 and python3.

mac/Pillow-tk-setup.patch

@@ -0,0 +1,14 @@
+diff -c /Users/john/Development/gtk-sources/Pillow-2.7.0/setup.py\~ /Users/john/Development/gtk-sources/Pillow-2.7.0/setup.py
+--- a/setup.py	Fri Jan  2 03:52:21 2015
++++ b/setup.py	Sun Mar 22 14:54:09 2015
+@@ -575,7 +575,7 @@
+             exts.append(Extension(
+                 "PIL._webp", ["_webp.c"], libraries=libs, define_macros=defs))
+ 
+-        if sys.platform == "darwin":
++        if _tkinter and sys.platform == "darwin":
+             # locate Tcl/Tk frameworks
+             frameworks = []
+             framework_roots = [
+
+Diff finished.  Sun Mar 22 20:37:52 2015