Faster utf7 encode (#373)
~40% faster for input with a mix of unicode and ascii chars
Fix _proc_folder_list quadratic runtime (#374)
2x faster _maybe_int_to_bytes for Python 2 (#375)
Fix minor typo (#376)
Catch the right exception in folder_status (#371)
* Catch the right exception in folder_status
* Remove useless try-except in folder_status
Fix error when INTERNALDATE is NIL
NIL is already converted to None during parsing.
The .upper() call on None will cause AttributeError. Catch this case
early and return None early.