Xpipefd wants the pipe descriptor to be closed in turfredir(), so
it pushes the redirection, but this breaks Xpopredir after normal
redirection. so we shuffle the Xpipefd redir to the bottom of the
stack.
add glob information to the word structure so we wont accidently
deglob quoted strings containing the GLOB. we store Globsize(word)
in in word->glob which avoids recalculating that values and the
check if a word should be globbed quick.
globlist() now substitutes the word inplace avoiding the copying
when all words are literals and avoids recursion.
minor cleanups: use list2str() in execeval(), move octal() to
unix.c, remove the (char*) casts to efree().