MAINT: Remove unneeded comment form arrayobject.h
MAINT: Remove unneeded include from ndarraytypes.h.
MAINT: Add some macros to noprefix.h

Some of these are probably new unprefixed macros, but adding them
makes for a bit more safety. The unprefixed macros will be deprecated
at some point, so this probably has no side effects.
MAINT: Gather NPY_SIZEOF* macros into one spot.
MAINT: Remove tabs from numpyconfig.h.
BUG: Fixup use of undefined macros and remove redundant code.

The npy_config.h file used SIZEOF_DOUBLE and SIZEOF_LONG_DOUBLE, neither
of which was defined in the included config.h file. That was fixed by
including numpyconfig.h. Doing so made the code dealing with Apple type
sizes redundant as it is already present in numpyconfig.h, so it was
removed.
MAINT: Remove newly defined non-prefixed macros from noprefix.h.

There was a chance that they could conflict with user defined macros.
Merge pull request #2888 from charris/fix-headers

Fix headers