Added paInt16, paInt8, format using new "pa_common/pa_convert.c" file.

Return error if opened in mono mode cuz not supported.
Add support for Pa_GetCPULoad();
Fixed timestamp in callback and Pa_StreamTime() (Thanks n++k for the advice!)
Check for invalid sample rates and return an error.
Check for getenv("PA_MIN_LATEWNCY_MSEC") to set latency externally.
Better error checking for invalid channel counts and invalid devices.

pa_mac_core/notes.txt

@@ -2,14 +2,16 @@ Notes on Core Audio Implementation of PortAudio
 
 by Phil Burk and Darren Gibbs
 
-Document last updated Feb 7, 2002
+Document last updated March 20, 2002
 
 WHAT WORKS
 
 Output with very low latency, <10 msec.
 Half duplex input or output.
 Full duplex on the same CoreAudio device.
-The paFLoat32 sample format.
+The paFLoat32, paInt16, paInt8, paUInt8 sample formats.
+Pa_GetCPULoad()
+Pa_StreamTime()
 
 KNOWN BUGS OR LIMITATIONS
 
@@ -18,10 +20,7 @@ devices. Note that some CoreAudio devices like the Roland UH30 look
 like one device but are actually two different CoreAudio devices. The 
 BuiltIn audio is typically one CoreAudio device.
 
-User formats other than the native paFloat32 are not yet supported.
-
-If you request a non-supported sample rate then you just get a 
-supported rate with no error messages.
+Mono doesn't work.
 
 DEVICE MAPPING