/b_allocRead            Allocate buffer space and read a sound file

int    - buffer number
string - path name of a sound file.
int    - starting frame in file (optional. default = 0)
int    - number of frames to read (optional. default = 0, see below)
bytes  - an OSC message to execute upon completion. (optional)

Allocates buffer to number of channels of file and number of samples
requested, or fewer if sound file is smaller than requested. Reads
sound file data from the given starting frame in the file. If the
number of frames argument is less than or equal to zero, the entire
file is read.

Asynchronous. Replies to sender with /done when complete.