Internal standardization of bounds 
Internal standardization of bounds 

Use a  numpy N x 2 array for bounds througout, with -np.inf and np.inf for absent lower and upper bounds. _clean_inputs now converts to a N x 2 array and this format is used in all other functions.
grlee77/scipy,e-q/scipy,matthew-brett/scipy,mdhaber/scipy,Stefan-Endres/scipy,endolith/scipy,rgommers/scipy,anntzer/scipy,zerothi/scipy,Eric89GXL/scipy,anntzer/scipy,anntzer/scipy,nmayorov/scipy,grlee77/scipy,ilayn/scipy,Stefan-Endres/scipy,ilayn/scipy,andyfaff/scipy,zerothi/scipy,endolith/scipy,WarrenWeckesser/scipy,endolith/scipy,tylerjereddy/scipy,WarrenWeckesser/scipy,e-q/scipy,WarrenWeckesser/scipy,scipy/scipy,mdhaber/scipy,zerothi/scipy,andyfaff/scipy,ilayn/scipy,mdhaber/scipy,nmayorov/scipy,zerothi/scipy,nmayorov/scipy,perimosocordiae/scipy,anntzer/scipy,Stefan-Endres/scipy,zerothi/scipy,nmayorov/scipy,grlee77/scipy,vigna/scipy,Stefan-Endres/scipy,rgommers/scipy,rgommers/scipy,andyfaff/scipy,grlee77/scipy,nmayorov/scipy,WarrenWeckesser/scipy,ilayn/scipy,Eric89GXL/scipy,perimosocordiae/scipy,andyfaff/scipy,matthew-brett/scipy,vigna/scipy,endolith/scipy,scipy/scipy,Eric89GXL/scipy,andyfaff/scipy,ilayn/scipy,Eric89GXL/scipy,scipy/scipy,Stefan-Endres/scipy,ilayn/scipy,scipy/scipy,anntzer/scipy,grlee77/scipy,matthew-brett/scipy,mdhaber/scipy,e-q/scipy,tylerjereddy/scipy,endolith/scipy,rgommers/scipy,endolith/scipy,vigna/scipy,tylerjereddy/scipy,matthew-brett/scipy,zerothi/scipy,mdhaber/scipy,Eric89GXL/scipy,mdhaber/scipy,WarrenWeckesser/scipy,perimosocordiae/scipy,Eric89GXL/scipy,tylerjereddy/scipy,vigna/scipy,perimosocordiae/scipy,rgommers/scipy,Stefan-Endres/scipy,tylerjereddy/scipy,matthew-brett/scipy,WarrenWeckesser/scipy,perimosocordiae/scipy,perimosocordiae/scipy,vigna/scipy,e-q/scipy,e-q/scipy,andyfaff/scipy,anntzer/scipy,scipy/scipy,scipy/scipy