Add FILE_LICENCE declarations to almost all files that make up the
various standard builds of gPXE.

Eliminate the potential for mismatches between table names and the
table entry data type by incorporating the data type into the
definition of the table, rather than specifying it explicitly in each
table accessor method.

Intel's C compiler (icc) chokes on the zero-length arrays that we
currently use as part of the mechanism for accessing linker table
entries.  Abstract away the zero-length arrays, to make a port to icc
easier.

Introduce macros such as for_each_table_entry() to simplify the common
case of iterating over all entries in a linker table.

Represent table names as #defined string constants rather than
unquoted literals; this avoids visual confusion between table names
and C variable or type names, and also allows us to force a
compilation error in the event of incorrect table names.

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).

Kill off the static single net device and move to proper dynamic
registration (which we need with the new device model).

Break the (flawed) assumption that all network-layer protocols can use
ARP; such network-layer protocols (i.e. IPv4) must now register as an ARP
protocol using ARP_NET_PROTOCOL() and provide a single method for checking
the existence of a local network-layer address.

implementation allows for only one, and does so without compromising on
the efficiency of static allocation).

Link-layer protocols are cleanly separated from the device drivers.

Network-layer protocols are cleanly separated from individual network
devices.

Link-layer and network-layer protocols are cleanly separated from each
other.

it with metadata in the pkb structure.  This is required since UNDI will
want to be able to parse the link-layer header without destroying it.