Added single_session argument for OC5 workaround

The OCS API in OC5 has trouble when reusing the same session.

This fix adds an argument single_session that can be set to False to
force reauthenticating for every call (not recommended).
Merge pull request #1 from soalhn/ocs_constants

Add some OCS constants - will be used later
Merge pull request #13 from PVince81/oc5-session-workaround

Added single_session argument for OC5 workaround
Merge pull request #11 from soalhn/master

Added function get_config() - ownCloud config information
Added supported ownCloud versions
PEP8 - fix function get_config()
Merge pull request #16 from soalhn/pep8-get_config

PEP8 - fix function get_config()
refactor out of init.py
Adds authors to Readme
Remove request import
Merge pull request #2 from PVince81/master

Merge @PVince81:master
Added function share_file_with_user(), class UserShare() and make use of constant OCS_SHARE_TYPE_LINK in functions.