AsfUsbSerial: Fix bug in sending code.
The number of bytes given to give to udi_cdc_write_buf() function is calculated right, but then the wrong variable is used. When the host stops accepting data this probably results in udi_cdc_write_buf() blocking and the watchdog resetting the MCU.
BUT the resetting issue is still present to something else is going on.
Finally fix the crash with ASF's USB CDC when host stops accepting data.
The problem is that udi_cdc_get_free_tx_buffer() is incorrect.
So now we ship a patch and have the compile script patch udi_cdc.c.
compile scripts: Throw all generated files into out/ subdirectory.