[lwip-members] dhcp leon changes

[Jani Monoses]

Hi
Leon are you still working on the dhcp/netif thing or did things settle?
I am asking so I don't interfere with your possible further changes.
the code in CVS right now has circular dependencies of dhcp.h netif.h which 
cause
some warnings in dhcp.h and ip.h (implicit decl of netif.h)
I put a struct netif; insetad of include <netif.h> in these files but maybe 
someone
as a better solution.
Also a compile error in dhcp.h (missing / at beginning of comment before 
options_in_len.
And lots of C++ style comments ;)

Jani.