Pdfextract

1. Uploaded to the PyPI.

1. Added support for multiple source documents.
Now you can merge the extracted pages in the very same command,
no matter where these pages are extracted from.

1. Rewritten from scratch, using PyPDF2, pure python.
You can extract, remove, duplicate or rearrange pages as you like.

1. Added support for multiple range,
but changed commandline options a lot.
No more direct option for removing pages,
but this is likely to be added in later codes,
in the form of syntactic sugar for extracting.
`-f', `-l' and `-r' was removed, while `-p' took their place.

1. `eval' is evil. no `eval' is also nice.

1. Let's check the sanity of that eval's argument. :)
And also restrict the execution environment of that eval
to one that only contains the `subprocess' module,
but it seems to be of trivial use
as `subprocess' can do a lot of evil only by itself, :(
and the code below does not work as i expected!
The environment was not restricted at all! :(

restrict_env = {'subprocess':__import__('subprocess')}
eval('print(globals())', restrict_env)

The reason is in the docs,
`if the globals dictionary is present and lacks ‘__builtins__’,
the current globals are copied into globals
before expression is parsed'.
So, am i going to write a python sandbox?
No! At least not now! Stop here! Escaping is enough.
Let's assume it is enough. :)