DOC: Misc single to double backticks fixes.
DOC: Misc single to double backticks fixes.

As usual, single backtics are for references, double for verbatim.

Rewrap the paragraph when necessary,

Change also a couple of mode=xxx to mode='xxx' as well.

jakirkham/numpy,charris/numpy,mhvk/numpy,pbrod/numpy,anntzer/numpy,jakirkham/numpy,madphysicist/numpy,anntzer/numpy,numpy/numpy,mhvk/numpy,pbrod/numpy,mhvk/numpy,mhvk/numpy,mattip/numpy,simongibbons/numpy,rgommers/numpy,madphysicist/numpy,mattip/numpy,jakirkham/numpy,endolith/numpy,endolith/numpy,endolith/numpy,madphysicist/numpy,anntzer/numpy,charris/numpy,anntzer/numpy,rgommers/numpy,pdebuyl/numpy,pdebuyl/numpy,madphysicist/numpy,rgommers/numpy,seberg/numpy,rgommers/numpy,madphysicist/numpy,charris/numpy,simongibbons/numpy,pbrod/numpy,seberg/numpy,seberg/numpy,pdebuyl/numpy,simongibbons/numpy,mattip/numpy,pbrod/numpy,pdebuyl/numpy,seberg/numpy,simongibbons/numpy,pbrod/numpy,mattip/numpy,simongibbons/numpy,endolith/numpy,numpy/numpy,charris/numpy,numpy/numpy,mhvk/numpy,numpy/numpy,jakirkham/numpy,jakirkham/numpy