Patches: fixes for bodystructure foreign encoding processing

[José Dapena Paz <jdapena igalia com>]

	Hi,

	These two fixes are for fixing encoding processing in bodystruct
tinymail:
	* Fixed filename processing
	* Fixed also get_decoded_stream method, which was wrong.

Changelog entries:
	* libtinymail-camel/tny-camel-bs-mime-part.c: properly decode
	filename field.

	* libtinymail-camel/tny-camel-bs-mime-part.c
	(..._get_decoded_stream_default): properly decode text/plain
	messages as utf8.


-- 
José Dapena Paz <jdapena igalia com>
Igalia