Remove paramiko hacks
Remove two paramiko hacks done in client.py. They both seem like very old workarounds and their functionality can be achieved through official paramiko APIs.
The first one set the banner timeout for paramiko Transport to 45 seconds. banner_timeout can be set in paramiko SSHClient.connect or with Transport.banner_timeout, I went with connect as it seems to be the expected way to do it. This might be a breaking change if someone is using the SSHLibrary SSHClient.client directly as then the timeout will be the default 15 seconds.
The second one is a workaround for % symbols in file paths reported in 2012: http://code.google.com/p/robotframework-sshlibrary/issues/detail?id=55 . It seems this has been fixed in paramiko in 2014 here: https://github.com/paramiko/paramiko/commit/6e9abc39cfff94e0dc36ebe6b939caa8d2eafee0 . As it has been fixed for so long I hope everyone moved on to newer paramiko and this is not needed anymore.
Also removed small remaining Python 2 compatibility.
The Read Until With Encoding Errors On Strict test is failing because of #431, issue #465 .