DOC: Add rq to __init__, correct rq docstring.

This function works fine on rectangular and complex matrices.  No
ideal why the docstring didn't reflect that.
MAINT: stats: fix a typo [skip ci]
Merge pull request #4132 from WarrenWeckesser/doc-typo

MAINT: stats: fix a typo [skip ci]
BUG: ZeroDivisionError in scipy.sparse.linalg.lsqr
Minor addition to docstrig about return parameters
Merge pull request #4144 from bsipocz/docs_optimize_brute_minor_addition

DOC: Minor addition to docstrig about return parameters
Merge pull request #4142 from ogrisel/fix-sparse-lsqr

BUG: ZeroDivisionError in `scipy.sparse.linalg.lsqr`
MAINT: remove use of deprecated numpy API in lib/lapack/ f2py wrapper.

Fixes a compile error with numpy 1.10-dev due to numpy PR 5270.
Closes gh-4151.
Merge pull request #4153 from rgommers/f2py-deprecated-api

MAINT: remove use of deprecated numpy API in lib/lapack/ f2py wrapper.
MAINT: optimize: clean up Zeros code

* Use standard C header file <math.h>
* Decouple implementation from interface in zeros.h
  (expanded out the ERROR macro for readability)
* Don't use static variables, they make code non-reentrant
  and hinder compiler optimizations
* Indentation, {}, split multi-statement lines
Merge pull request #4159 from larsmans/c-fixes

MAINT: optimize: clean up Zeros code
Merge pull request #4099 from ewmoore/rq_init

DOC: Add rq to __init__, correct rq docstring.