Forgoten pull requests from ln/xmpp4r

Here are ~~5~~ 3 pull requests from the abandoned ln/xmpp4r repo. I used them in production for several months without issue.

IIRC, as many tests passed before and after I merged theses pulls.

Merge pull-14 mironov / Attributes are normalized twice in parse method
commit '3504da147eb7490835d57b56686771d8470f5569'

~~Merge pull-17 ppgengler / A few bug fixes and one improvement
commit '1a480f40fa34c68f2ff807804a83f0dd01cf5737'~~

Merge pull-19 mbisha / Fixed file transfer file corruption on Windows
commit '67bff803480e49a39fdb058921bdcd5eccfd7fe0'

Merge pull-21 ronny / Fixed a typo in Jabber::MUC::MUCClient#send_affiliations
commit '13d41833fd3380ae28b58c561f39df5524a97efe'

~~Merge pull-25 ShogunPanda / X facebook platform
commit '795c6a98000d7c6cc3ee7225f1ff445c0c9ba5fe'~~