Use .encode() instead of str() to support unicode arguments.

str() throws an UnicodeEncodeError for code points that cannot be
represented in 7-bit ASCII. This makes it impossible to use any
non-ASCII characters in module arguments. Using encode('utf-8')
gives the desired result.
Repair issue #3447
Merge pull request #3443 from ajsalminen/arg_unicode_fix

Use .encode() instead of str() to support unicode arguments.
Merge pull request #3450 from tonk/sudo

Repair issue #3447
Make it possible to tell paramiko to not record new host keys, which can be slow with a large number of hosts.
-c ssh is preferred in most cases if you have ControlPersist available, otherwise if you are comfortable you
can turn off recording while leaving host key checking on, etc.
Update changelogs
Update releases
Update changelog
Slight revisement to configuration file comment.
Fixup changelog dates