Add pylint checks

[mzfr]

With this we will be able check our addons with pylint. The output will look like:

File name	Line no	Message
kodi.py	24	Imports from package xbmc are not grouped
url_dispatcher.py	99	Line too long (165/120)

Currently all the checks are enabled on line 17 in .pylintrc but we can then disable the ones we don't want.