BUG: binom_test failed for some values, closes issue #2384
TST: binom_test more unittests for edgecase and close
REF: binom_test add shortcut for special case (unit tests previous commit)
DOC: remove outdated TOCHANGE.txt
DOC: remove not so useful Py3K.txt
DOC: move material from README to HACKING, remove outdated parts, and move LATEST to README
[ENH] sparse.linalg.LinearOperator: add +, *, **

Enhances LinearOperator such that they can be
added, multiplied and exponentiated.
[TST] sparse.linalg.LinearOperator: test +, *, **
MAINT,TST: use isintlike and add __pow__ test
MAINT: use subclasses for LinearOperator operations
LinearOperator: make it callable
LinearOperator: catch ValueError and return NotImplemented
BUG: sparse/linalg: fix NotImplemented vs exceptions in __sub__
BUG: sparse/linalg: pep8 fixes
BUG: sparse/interface: improve test coverage + fix a bug in PowerLinearOperator
BUG: sparse/interface: return NotImplemented only when operand type is unknown

Failures in matching shape etc. should raise ValueErrors on operation.
ENH: sparse.interface: document and test the args attribute of LinearOperators
Merge pull request #2692 from andrenarchy/linearoperators

ENH: sparse.linalg.LinearOperator: add +, -, *, and ** operators

These commits enhance the LinearOperator class in sparse.linalg such that they
can be added/substracted, multiplied and exponentiated. Unit tests are included
and should cover all cases. The unit tests for LinearOperator were also
restructured a bit.
Added statement about BivariateSpline being an abstract base class

Closes #2262.
Merge pull request #2740 from Juanlu001/patch-1

DOC: interpolate: Added statement about BivariateSpline being an abstract base class