Unix Rio Utility Code

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.

Fix some compiler warnings.

New function: get_flist_rio

Returns a pointer to the flist struct for the given file number.

Use strncpy for safety

New command line option -g to print a list of playlists on the device.
The output isn't too pretty but it works.

Set the playlist name in get_playlist_rio

Fix rio_num() function by changing logic || to bitwise |.

Also added some logging.