Added pickling tests for Season and Episode classes
Reduce exceptions verbosity

All created exception already log its message. There is no need to log
it beforehand.
Merge branch 'master' of https://github.com/BenoitZugmeyer/pytvdbapi into BenoitZugmeyer-master

Conflicts:
	pytvdbapi/api.py
Merge branch 'master' of https://github.com/BenoitZugmeyer/pytvdbapi into BenoitZugmeyer-master

Conflicts:
	pytvdbapi/api.py