Add condition matching capability to only account for one or more subset of channel directions to radius.

A lot of tiny tidy up edits

A bug in end of image handling fixed, which could mean some T.85 images would
screw up.

The len variable can, in certain situations (large burst of incoming non-SLIN audio),
exceed the size of the on-stack frame buffer, which causes ftdm_buffer_read_loop() to
overwrite the dt_buffer pointer.

Use ftdm_min() to make sure len (after conversion to SLIN units) isn't larger
than the frame buffer size.

Also adds are couple more code comments.
Signed-off-by: Stefan Knoblich <stkn@openisdn.net>

Signed-off-by: Stefan Knoblich <stkn@openisdn.net>

combination

Improvements to image flattening in spandsp's image translate code

CGI specifies that REQUEST_URI is relative to the root (and does not include scheme name, hostname, port)