[BusyBox] modifications to copy_file()

[Glenn McGrath]

Im preparing to renovate the archiving code after 1.0

Currently there is an overlap of functionality between copy_file() (used
by cp, mv, install, rpm) and data_extract_all (used by all the
unarchiving applets)

Ive added a new function called create_file that is called by
copy_file() and should eventually replace data_extract_all completely.

The current patch is at
http://people.debian.org/~bug1/busybox/bb_copy_file_create_file.patch

Im not any hurry with this patch, its just a good break point.


Glenn