Assuming that you're just trying to make everything readable/writable and directories executable, you could just do:

chmod -R a=rX,u=rwX *
[download]

I believe this to be POSIX compliant, but I could be wrong. This works under Linux. It will not dispell execute perms on plain files that already have them, but this could be rectified with a a-x before the rest of the symbolic mode expression.