`py-underscore-word-syntax-p' customization has no effect, lp:1100947, again

Thanks Paul Pogonyshev for the patch 
`py-newline-and-indent' leaves eol whitespace, lp:1100892, fixed

new boolean `py-newline-delete-trailing-whitespace-p' 
Delete trailing whitespace maybe left by `py-newline-and-indent'
py-fill-paragraph exceeds max eval depth, lp:1102010

fixed