CLN: Add .gitattribtes to fix crlf issues.
CLN: Change CRLF --> LF
BLD: Add binary files to gitattributes too
DOC: timeseries.rst/timedelta not building properly
DOC: partial string indexing docs in timeseries.rst (GH3938)
Merge pull request #3915 from jtratner/fix-crlf-in-repo

CLN: Fix CRLFs in repo + add .gitattributes
Merge pull request #3939 from jreback/partial_string

DOC: partial string indexing docs in timeseries.rst (GH3938)
CLN: Remove unused Exceptions throughout
CLN: Remove 'DateConversionError' that is never raised anywhere

CLN: Remove TimeSeriesError that was never used

CLN: Remove unused 'PanelError'