doc update and better versionning method

setup.py

@@ -1,8 +1,11 @@
 # This file is autogenerated by edgy.project code generator.
 # All changes will be overwritten.
 
+import os
 from setuptools import setup, find_packages
 
+root_dir = os.path.dirname(os.path.abspath(__file__))
+
 tolines = lambda c: list(filter(None, map(lambda s: s.strip(), c.split('\n'))))
 
 
@@ -12,10 +15,19 @@ def read(filename, flt=None):
         return flt(content) if callable(flt) else content
 
 
+# Py3 compatibility hacks, borrowed from IPython.
 try:
-    version = read('version.txt')
-except:  # pylint: disable=bare-except
-    version = 'dev'
+    execfile
+except NameError:
+
+    def execfile(fname, globs, locs=None):
+        locs = locs or globs
+        exec(compile(open(fname).read(), fname, "exec"), globs, locs)
+
+
+version_ns = {}
+execfile(os.path.join(root_dir, 'bonobo/_version.py'), version_ns)
+version = version_ns.get('__version__', 'dev')
 
 setup(
     name='bonobo',