Unix Rio Utility Code

clean up compiler warning in id3 parser

clean up compiler warnings in mp3 parser

clean up compiler warnings

use libusb 1.0 API for device access

set librioutil libadd flags corectly

update configury and check for libusb 1.0

update configury and check for libusb 1.0

quiet compiler warnings

Complete the switch to new logging functions. The rio_log() function is replaced by
debug(), warning(), and error(). The new logging functions don't depend on the rio struct,
and the debug level is now stored globally. Logging levels are defined in riolog.h

The output should still look the same as before.

Fix overflow problems with extremely long songs (ie audiobooks) by declaring some things as
unsigned.

Also properly recognize playlist files on the device as such.