R&D on modules

``` python
>>> import modtest1
>>> modtest1
<module 'modtest1' from 'modtest1.py'>
>>>
>>> modtest1.var1
1
>>>
>>> import modtest1 as mt1
>>>
>>> mt1
<module 'modtest1' from 'modtest1.py'>
>>>
>>> mt1.var1
1
>>> mt1.var1 = 2
>>>
>>> modtest1.var1
2
>>> reload(modtest1)
<module 'modtest1' from 'modtest1.pyc'>
>>>
>>> mt1.var1
1
>>> modtest1.var1
1
>>>
```
