Add basic sysconfig file

Signed-off-by: Peter Lemenkov <lemenkov@gmail.com>
Initial commit of files required for running with systemd

Signed-off-by: Peter Lemenkov <lemenkov@gmail.com>
Enable systemd socket activation

Signed-off-by: Peter Lemenkov <lemenkov@gmail.com>
Enable systemd notification

Signed-off-by: Peter Lemenkov <lemenkov@gmail.com>
Merge pull request #11 from lemenkov/systemd

A very basic systemd support
Move out accept() code into its own thread. This removes annoying
ability for one client that connects to the control socket and just
hangs onto that connection without sending any data to block other
clients trying to talk to the same socket. In addition, it adds
possibiluty for the local socket client to reduce overhead by keeping
the connection open instead of going through connect(), write(),
close() cycle on every command, which might be imporant to handle
high-CPS traffic loads. This works fine with our python client code,
but needs more testing to ensure this won't screw up existing clients,
i.e. opensips, kamalio and such, in which case we would make it opt-in
feature, to be made default in 3.0 or so.

This also makes it relatively easy to add support for TCP control
channel as well as for multiple stream-based control sockets (i.e.
tcp+unix domain and or several tcp/several unix domain at the same
time).
ensure this won't screw up existing clients
Add few more new files that are necessary now.
Add config_std.h.
Don't pring debug message if no debug has been built in.
Add rtp_info.h rtpp_command_private.h into SRCs.
Fix double inclusion of the "rtpp_types.h".
Remove pthread.h include, it's unused.
Further split command accept/io code and actually add support for
accepting control connections via multiple parallel channels, so that
it's possible to mix and match, additional channels are enabled
by specifying `-s' multiple times, i.e.:

rtpproxy -s /tmp/rtpproxy1.sock -s udp:127.0.0.1:32433 -s /var/run/rtpproxy.sock

Which would create two unix domain and one UDP control sockets
each can be used independently.

Add 3 new types of control sockets:

 o systemd: accept commands via systemd (linux-only now). ;

 o cunix: like "unix" (i.e. unix-domain socket), but allow client to
   keep connection open between commands to reduce overhead and also
   possibly improve reliability by pre-allocating system resources
   necessary. Added to keep "unix" type fully compatible with legacy
   clients that mught be expecting rtpproxy to close connection after
   each command;

 o stdio: take commands from stdin, reply to stdout. Also requires
   the rtpproxy to be run in the "foreground" mode (i.e. -f).
Add few more source files, filter config.h out of PKGFILES.
Add stdint.h to main.c, re-gen automake
Re-gen after addition of the systemd support and few new files.
Add missing <stdint.h>
Add new stat: nsess_complete, that is number of sessions that had
both UAC and UAS sides filled in.
Raise RTPC_MAX_CONNECTIONS to something more reasonable.
o Update nsess_complete / nsess_created more efficiently.

o Rework command handling path to work much more efficiently
and do not add mandatory processing delay to each command. This
should allow much higher CPS to be processed by a single instance.