For the few peripherals where it was being used (eg. uart, spi, etc) the output port
has been renamed to "int_o".

The only peripheral that was not touched is "wb_eic.vhd", because this one is being used
by wbgen, and it would require users to update their wbgen tool as well. So, until a new
tool is introduced, wbgen-generated interrupt controllers will have an output port called
wb_int_o".

Added:
- asynchronous SRAM bus -> Wishbone bridge (wb_async_bridge)
- Conmax interconnect (wb_conmax)
- GPIO port (wb_gpio_port)
- Very simple timer (wb_simple timer)
- Simple UART (wb_uart)
- Vectored Interrupt controller (wb_vic)
- Virtual UART (mmapped FIFO, wb_virtual_uart)
- wbgen2 core generator libraries (wbgen2)