fixed syntax error
Add Wiznet W5100 to menuconfig

Wiznet W5100 is the ethernet chip used on the Arduino
Ethernet Shield.  Actually it has a full TCP/IP stack
on board, but it can be used in Raw-MAC-mode.

For Ethersex it is an alternative to ENC28J60, currently
it's not a goal to have both available simultaneously.
Hence the ENC28J60 IP/MAC-configuration is simply re-used.
Configure SPI for W5100 as needed.
Ignore vim .swo swapfiles also.
ignore meta.defines
Prepare uIP stack for W5100 ethernet controller
Reset W5100 and disable interrupts initially.

Besides read RMSR register when debugging is enabled,
more or less to prove that W5100 is connected :-)
Configure W5100 for MAC raw mode, poll interrupt register.
implement packet reception
Implement w5100_txstart.
fix w5100 debugging output
typo
add Arduino Uno profile