Small tweak for media I/O in proxy mode, don't silence frame just because no codec. Needed for H.323 fax.

Added tracing for error conditions in mod_spandsp

Fixed correct media "frames/packet" for G.711, default to 20ms worth.

FS-4614 --resolve update to dynamic line buffer and use internal buffering to boot for file I/O on preprocessing XML

Also add a few more PH_CONTROL_IND message types.
Signed-off-by: Stefan Knoblich <stkn@openisdn.net>