This avoids hanging up a device that is no longer attached to the session, in the
         weird situation where the FreeSWITCH core takes an awful lot of time (more than 3 seconds)
         to come around to acknowledge the SIGEVENT_STOP signal.

FS-3564 --resolve Fix build for mod_skypopen, problem occurs after latest changes for chat interface

Add application flag zombie_exec so registered applications can apply to be executed on channels that are already hungup, like the inline exec this is only limited to a small family of apps that do not use the channel for audio.

change -hp to -rp, add -lp and -np, no priority flags means auto which will do -rp if you have > 1 cpu

         - Misc fixes to log messages to aid debugging
         - Added ftdm ioread command to read media from the channel
         - Modified the ftdm_channel_open() API to return FTDM_EBUSY if the channel is already open

[FreeTDM] Add missing newline in "Failed to configure span" error message in ftdm_configure_span_channels().
Signed-off-by: Stefan Knoblich <stkn@openisdn.net>