the default algorithm is introselect

The documentation needs to be in umathmodule.c as that is where ldexp
and frexp and defined. I moved the current documention from
add_newdocs.py to ufunc_docstrings.py, manually translated them into C
strings, and inserted them into umathmodule.c.

Closes #2354.

also drop sometrue/alltrue link, its equivalent to any/all.

Run the 2to3 ws_comma fixer on *.py files. Some lines are now too long
and will need to be broken at some point. OTOH, some lines were already
too long and need to be broken at some point. Now seems as good a time
as any to do this with open PRs at a minimum.

Now is as good a time as any with open PR's at a low.