ok stsp@

suggested by millert ok thomas_adam

Explicitly cast "char" to "unsigned char" when assigned to "int" to prevent sign extension from breaking comparions against EOF or passing invalid arguments to ctype functions.

Original commit message by deraadt: (unsigned) means (unsigned int) which on ptrdiff_t or size_t or other larger types really is a range reduction... Almost any cast to (unsigned) is a bug.

This was pointed out by uwerler in IRC. ok stsp

ok tracey

fix rash pointer change in last edit

correct a lot of incorrect error handling adjust copyrights