[csplit] Moved several POSIX functions with minor changes to posixc.library
drwxr-xr-x - AROS
drwxr-xr-x - binaries
drwxr-xr-x - conf
drwxr-xr-x - contrib
drwxr-xr-x - documentation
drwxr-xr-x - ports
drwxr-xr-x - www