optimize read mechanics for remote servers using ioctl to determine number of bytes...

optimize read mechanics for remote servers using ioctl to determine number of bytes available for reading.
in general, this should provide an improvement which scales with the amount of data being transferred:
* small transfers will incur a small amount of overhead from potentially unneeded memory as I try to account for a bug in FIONREAD which returns a number that is smaller than the actual number of bytes available for read on a socket
* large transfers will no longer require any copies of the data

on systems which do not provide the FIONREAD ioctl(), old functionality will be used
this should work on windows, though I (obviously) can't test it myself

thus ends the longest commit message I have ever written

git-svn-id: svn+ssh://svn.enlightenment.org/var/svn/e/trunk/ecore@66063 7cbeb6ba-43b4-40fd-8cce-4c39aea84d33