Remove from ObjLibraryClient 6 methods which should be called from Library instances (objects cleanup).
Add documentation for upload_file() and paste_content() methods. Make upload_payload() method private.
Rename get_current_history() to get_most_recently_used_history().

The current history is not necessarily the most recently used one.
The Galaxy API method to get the current history has been removed in commit

https://bitbucket.org/galaxy/galaxy-central/commits/5ce55f9f2923dcdf27150cce3addd6e1ff3782d7
Workaround "urllib3.exceptions.ProtocolError not wrapped" bug in Requests 2.4 .

See https://github.com/kennethreitz/requests/issues/2192 .
Merge pull request #86 from nsoranzo/objects_cleanup

ObjLibraryClient cleanup + misc fixes