show_setting() and related functions now return an "actual length" in the
style of snprintf(). This is to allow consumers to allocate buffers large
enough to hold the formatted setting.
names.
Add "dev" pointer in struct net_device to tie network interfaces back to a
hardware device.
Force natural alignment of data types in __table() macros. This seems to
prevent gcc from taking the unilateral decision to occasionally increase
their alignment (which screws up the table packing).
Introduce new {show,set,clear}_setting() that take a struct setting *
rather than a const char *.
set_setting() handles calling clear_setting() when appropriate, so that
individual setting types don't have to check for empty strings.