fix setup.py (install was broken)

Import `version` in the `setup.py` requires periscope to be installed. But, of couse, it isn't until setup.py install finish (installing, for example the dependency BeatifulSoup). 

Look it yourself:

```
tin@morochita:~/lab$ sudo pip install periscope
[sudo] password for tin: 
Downloading/unpacking periscope
  Downloading periscope-0.2.4.tar.gz
  Running setup.py egg_info for package periscope
    Traceback (most recent call last):
      File "<string>", line 16, in <module>
      File "/tmp/pip_build_root/periscope/setup.py", line 2, in <module>
        from periscope import version
      File "periscope/__init__.py", line 1, in <module>
        from periscope import *
      File "periscope/periscope.py", line 38, in <module>
        import plugins
      File "periscope/plugins/__init__.py", line 20, in <module>
        from Subtitulos import Subtitulos
      File "periscope/plugins/Subtitulos.py", line 20, in <module>
        from BeautifulSoup import BeautifulSoup
    ImportError: No module named BeautifulSoup
    Complete output from command python setup.py egg_info:
    Traceback (most recent call last):

  File "<string>", line 16, in <module>

  File "/tmp/pip_build_root/periscope/setup.py", line 2, in <module>

    from periscope import version

  File "periscope/__init__.py", line 1, in <module>

    from periscope import *

  File "periscope/periscope.py", line 38, in <module>

    import plugins

  File "periscope/plugins/__init__.py", line 20, in <module>

    from Subtitulos import Subtitulos

  File "periscope/plugins/Subtitulos.py", line 20, in <module>

    from BeautifulSoup import BeautifulSoup

ImportError: No module named BeautifulSoup
```

This patch simplify the layout because... why we need a silly `version.py` module?