BLD: add setup_requires in setup.py so numpy can be used with buildout

Numpy is a setup-time dependency due to some .h files, but is not declared as such. This causes tools like buildout to fail.
CLN: Remove unused Exceptions throughout
CLN: Remove 'DateConversionError' that is never raised anywhere

CLN: Remove TimeSeriesError that was never used

CLN: Remove unused 'PanelError'
BLD: Add useful shortcuts to Makefile

BLD: Add doc task to Makefile
BLD: Make doc not silent

BLD: add tasks to .PHONY

BLD: Only remove *.pyc with make build
ENH: update bundled ujson to latest v1.33
BUG: ujson fix for VC++
ENH: enable support for iterator with read_hdf in HDFStore (GH3937)

DOC: update v0.11.1.rst
Merge pull request #3803 from jtratner/makefile-updates

BLD: Add useful shortcuts to Makefile
Merge pull request #3949 from jreback/hdf_iterator

ENH: enable support for iterator with read_hdf in HDFStore (GH3937)
Merge pull request #3903 from ejnens/master

BLD: add setup_requires in setup.py so numpy can be used with buildout
API: more consistency in the to_datetime return types (give string/array of string inputs) (GH3888)
BUG: truncate will only try to convert to dates for an all_dates index
Merge pull request #3890 from jreback/to_datetime

API: (GH3888) more consistency in the to_datetime return types (given string/array of string inputs)
BUG: (GH3925) Indexing with a string with seconds resolution not selecting from a time index
Merge pull request #3931 from jreback/time_indexing

BUG: (GH3925) partial string selection with seconds resolution
Merge pull request #3921 from jtratner/remove-unused-exceptions

CLN: Remove unused Exceptions
Merge pull request #3946 from Komnomnomnom/ujson-update

ENH: update bundled ujson to latest v1.33