refactor POS/views.py
refactor POS/views.py

PEP8 most of the file (except some argument names)
fix internal server error on editing pos with no fitting
fix handling of invalid corp names

nyrocron/eve-wspace,marbindrakon/eve-wspace,Unsettled/eve-wspace,Zumochi/eve-wspace,mmalyska/eve-wspace,proycon/eve-wspace,gpapaz/eve-wspace,mmalyska/eve-wspace,hybrid1969/eve-wspace,Zumochi/eve-wspace,gpapaz/eve-wspace,mmalyska/eve-wspace,Maarten28/eve-wspace,gpapaz/eve-wspace,Unsettled/eve-wspace,acdervis/eve-wspace,evewspace/eve-wspace,marbindrakon/eve-wspace,nyrocron/eve-wspace,Maarten28/eve-wspace,proycon/eve-wspace,nyrocron/eve-wspace,acdervis/eve-wspace,proycon/eve-wspace,marbindrakon/eve-wspace,evewspace/eve-wspace,hybrid1969/eve-wspace,Maarten28/eve-wspace,hybrid1969/eve-wspace,Maarten28/eve-wspace,Unsettled/eve-wspace,hybrid1969/eve-wspace,Zumochi/eve-wspace,evewspace/eve-wspace,mmalyska/eve-wspace,Zumochi/eve-wspace,nyrocron/eve-wspace,acdervis/eve-wspace,gpapaz/eve-wspace,marbindrakon/eve-wspace,acdervis/eve-wspace,proycon/eve-wspace,Unsettled/eve-wspace,evewspace/eve-wspace