take care for indents in credits
Merge pull request #162 from vbkaisetsu/credit-indent

take care of indents in credits
Merge branch 'fix_and_unify_autosave' of github.com:kyouryuukunn/renpy into devel

This puts the checks as to if we can autosave into loadsave, rather than
scattering them in various places in the code.
set quit_action by whether renpy has screen "yesno_prompt" or not
close yesno_prompt shown by Quit by rclick