Much improved sosend_*() functions

[Andrew Gallatin]

Andre Oppermann writes:
 > I have rewritten m_getm() to be simpler and to allocate PAGE_SIZE sized
 > jumbo mbuf clusters (4k on most architectures) as well as m_uiotombuf()
 > to use the new m_getm() to obtain all mbuf space in one go.  It then loops
 > over it an copies the data into the mbufs by using uiomove().  sosend_dgram()
 > and sosend_generic() are change to use m_uiotombuf() instead of sosend_copyin().

Hurray!  Thank you for doing this.  I'll try to check it
out with mxge soon, but it might be until next week.

Drew