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().
