DOC: Add vbench docs
MAINT: Lazy copy-pasted version-only function.
DOC: Link to vbench documentation.
Merge pull request #1559 from jseabold/vbench-recover

MAINT: Recover lost commits from vbench PR
ENH: Allow ARMA(0,0) in order selection
Merge pull request #1560 from jseabold/order-select-00

ENH: Allow ARMA(0,0) in order selection
ENH: Optimize Cython code. Use scipy blas function pointers.
DOC: Mention arma speed-ups in release notes
COMPAT: Try to use Python 2/3 function declaration.
TST: Suppress not assert on possible warning.