Dehack the setup.py syspath + moved py2conv

setup was doing something really ugly with the sys path to load version.py
without loading errbot.

This fixes it by loading the file independently.

It also moves py2conv.py to tools as it is not part of errbot itself.

setup.py

@@ -33,6 +33,8 @@
 if PY3 and py_version < (3, 3):
     raise RuntimeError('On Python 3, Errbot requires Python 3.3 or later')
 
+VERSION_FILE = os.path.join('errbot', 'version.py')
+
 deps = ['webtest',
         'setuptools',
         'bottle',
@@ -82,15 +84,30 @@
     deps += ['daemonize']
 
 src_root = os.curdir
-sys.path.insert(0, os.path.join(src_root, 'errbot'))  # hack to avoid loading err machinery from the errbot package
+
+
+def read_version():
+    """
+    Read directly the errbot/version.py and gives the version without loading Errbot.
+    :return: errbot.version.VERSION
+    """
+
+    variables = {}
+    if PY2:
+        execfile(VERSION_FILE, variables)
+    else:
+        with open(VERSION_FILE) as f:
+            exec(compile(f.read(), 'version.py', 'exec'), variables)
+    return variables['VERSION']
 
 
 def read(fname):
     return open(os.path.join(os.path.dirname(__file__), fname)).read()
 
 
 if __name__ == "__main__":
-    from version import VERSION
+
+    VERSION = read_version()
 
     args = set(sys.argv)
 
@@ -105,7 +122,7 @@ def read(fname):
     # under python2 if we want to make a source distribution,
     # don't pre-convert the sources, leave them as py3.
     if PY2 and args & {'install', 'develop', 'bdist_wheel'}:
-        from py2conv import convert_to_python2
+        from tools.py2conv import convert_to_python2
         convert_to_python2()
 
     setup(
@@ -156,6 +173,3 @@ def read(fname):
         src_root=src_root,
         platforms='any',
     )
-
-# restore the paths
-sys.path.remove(os.path.join(src_root, 'errbot'))