Fix strides when creating Python buffer
Explicitly set strides with negative number in test
When requesting Fortan order, don't return C order.
MAINT: merge scalarmathmodule into umath module

There is no good reason it needs to be its own module.
Also removes the undocumented pymath alter/restore functions.
BUG: Stricter checks for gufunc signatures

* Arguments, both input and output, must have at least as many
  dimensions as the corresponding number of core dimensions. In
  previous versions, 1's were prepended to the shape as needed.
* Core dimensions with same labels must have exactly matching
  sizes. In previous versions, core dimensions of size 1 would
  broadcast against other core dimensions with the same label.
* All core dimensions must have their size specified by a passed
  in input or output argument. In previous versions, core
  dimensions in an output argument that were not specified in an
  input argument, and whose size could not be inferred from a
  passed in output argument, would have their size set to 1.
TST: Stricter checks for gufunc signatures

Added euclidean_pdist to umath/umath_tests.c.src.

Modified tests to reflect new, stricter gufunc signature behavior.
Add additional testing
DOC: Stricter checks for gufunc signatures

Documented the the new behavior in c-api.generalized-ufuncs.rst.

Added PyUFunc_FromFuncAndDataAndSignature to c-api.ufunc.rst.
BUG: Make PyArray_PutTo respect writeable flag.

Closes #4465.
TST: Add some tests for ndarray.put.
DOC note the effect of #1866 in byteorder discussion
BUG: fix crash when using arange on datetime without dtype set
Merge pull request #5225 from juliantaylor/datetime-arange-crash

BUG: fix crash when using arange on datetime without dtype set
Merge pull request #5216 from charris/cleanup-gh-5132

BUG: Make PyArray_PutTo respect writeable flag.
BUG: fix build in c99 mode

The definition of off_t is located in sys/types.h and is not pulled
by other files when compiling in c99 mode instead of the default gnu89.
Closes gh-5231
Merge pull request #5233 from juliantaylor/off_t-fix

BUG: fix build in c99 mode
Merge pull request #5086 from mdboom/stride-fix

Fix how strides is set on Py_buffer object when the array is C-contiguous
Replacing list with generator compherension
Merge pull request #5238 from yuvallanger/patch-1

Replacing list with generator compherension
Merge pull request #5077 from jaimefrio/gufuncs_core_dim_no_broadcast

WIP: gufunc core dimensions should not broadcast