- no errno, use errno.h
- no redefinition of function parameters as local variables
[how did this ever work?!]
- malloc comes from stdlib.h
- NAME_MAX is prefered when available, it is POSIX
- strchr, strpbrk, strspn, strstr, strtol and strtoul can and
should be used from libc.
- remove tcl version of string.h, system header is good enough
(and if it doesn't have index, it would have been broken anyway)
