Separation of sis900.c and sis900.h in order to move most constant definition to sis900.h (many of those constants were corrected)

Clean up PCI detection, the pci-scan from Donald Becker were not used, just simple pci_find_*.

MII detection is modified to support multiple mii transceiver.

Bugs in read_eeprom, mdio_* were removed.

Lot of sis900 irrelevant comments were removed/changed and more comments were added to reflect the real situation.

Clean up of physical/virtual address space mess in buffer descriptors.

Better transmit/receive error handling.

The driver now uses zero-copy single buffer management scheme to improve performance.

Names of variables were changed to be more consistent.

Clean up of auo-negotiation and timer code.

Automatic detection and change of PHY on the fly.

Bug in mac probing fixed.

Fix 630E equalier problem by modifying the equalizer workaround rule.

Support for ICS1893 10/100 Interated PHYceiver.

Support for media select by ifconfig.

Added kernel-doc extratable documentation.