Revert "return 0 (false) from Client.connect(hostname,port) when DNS-lookup didn't succeed"

This reverts commit 6086a364f83b65b84bca57689210974d13401717.
Introduced two new methods:

powerOff():
This will put the enc28j60 module into the sleep mode.

powerOn():
This will wake up the enc28j60 module back from sleep mode.

Usage:

void loop()
{
  Ethernet.maintain();
  [...]
  Ethernet.getNetwork().powerOff();
}
Changed all debug printouts so that the strings are stored in flash.
Changed all debug printouts so that the strings are stored in flash.
Changed all debug printouts so that the strings are stored in flash.
Merge pull request #33 from nilrog/master

Store all DEBUG printouts in FLASH instead of RAM
don't allocate memory for udp-blocks if udp is disabled
cleanup data before connecting again
Fixed a syntax error.
Suppress compiler warnings due to GCC bug 34734.
Suppress compiler warnings due to GCC bug 34734.
Revert "Suppress compiler warnings due to GCC bug 34734."

This reverts commit 5da989bb8aba2d22f61de9a81fe73decf6739492.
Revert "Suppress compiler warnings due to GCC bug 34734."

This reverts commit 16a3f31cb4309491b9c22d9870ff7a0c5cba8da9.
Merge pull request #40 from nilrog/upstream

Fixed a syntax error introduced in pull request #33.
fix leaking client-data caused by race-condidion on remote close
Merge pull request #44 from ntruchsess/dev

fix #30, caused by leaked client.data-members when remote closed connection with no unread inbound data left. Add explicit check for state!=0 to detect this in client.close();
add a few more F-macros in debug output
fix ARP for outgoing UDP
Fixed compiler warning in _eatBlock.
Fixed compiler warning by rearranging class variables in declaration.