Updated some docstrings in core.py

 * Binary warning for CSV output, because if you don't, Excel gets upset when Python translates \r\n to \r\n\r\n
 * Cleaned up what looked like a couple of copy paste errors
yay
Added support for detecting unicode column headers

Also added tests!

Fix for kennethreitz#26
Merge branch 'unicodeheaders' of https://github.com/mwalling/tablib into develop
updated history
tox cleanups
setup.py changes
toxless
Created get_col method with tests and tutorial.rst update

Useful when you have multiple columns with the same header
Fix pickling (again). Unit tests still pass.
Fix also __slots__ to ensure proper unpickling
Added XLS import support
Added xlrd license to NOTICE.
Added xls detection.
Merge branch 'fix_pickle_bug_2' of https://github.com/cswegger/tablib into develop
Merge branch 'feature/xls-import' of https://github.com/xdissent/tablib into develop
Replace None with empty string before creating td
Merge branch 'html_None_fix' of https://github.com/mawaldne/tablib into develop
Added Mike Waldner to Authors.
#34
Adding documentation changes for append_col
Related #21