Support for s3 file handling
Update README and RELEASE for new S3 support
Update io.rst

added io.read_html
Merge pull request #3557 from cpcloud/html-typeerror-bug-fix

fix TypeError for display.multi_sparse == False
TST: to_html regards empty string labels as repeated labels GH3547
BUG: to_html regards empty string labels as repeated labels GH3547
Merge branch 'GH3547'

* GH3547:
  BUG: to_html regards empty string labels as repeated labels GH3547
  TST: to_html regards empty string labels as repeated labels GH3547
DOC: update RELEASE.rst
Merge pull request #3560 from cpcloud/period-index-unicode-evaling-3460

ENH: unicode of PeriodIndex returns valid Python code
DOC: update RELEASE.rst
DOC: tweak
Merge branch 'PR3536'

* PR3536:
  DOC: tweak
  Update io.rst
DOC: remove v0.12.0.txt from whats new
DOC: cleanup line endings
DOC: Added some decriptions to the Selection subsection of the Cookbook
Merge pull request #3559 from cpcloud/concat-invalid-args-exception-3481

ENH: raise useful error message on invalid concat arguments
Update docs noting handling of s3 locations.
Merge pull request #3504 from pjob/s3-support

ENH: Support reading from S3
BUG: fix panel.transpose arguments API bug

only show the ambiguous aliases as opposed to all key-value pairs

add release note