initial import of sccp-next

* remove the old files
* add a basic sccp.c, Makefile and remote build script
remove tests directory
update Makefile install target to use 644 permission
update sccp show version
add config loading / unloading / reloading
add a simple sccp show config CLI command
AST_MODULE is "chan_sccp"

This is the name used for example when doing a "core set debug".
remove some debug log
update log message when there's an error in the configuration
use asterisk style in comments
add server submodule (WIP)
minor fix in server submodule
add a minimalist "sccp show sessions" CLI command
rename sccp_server_loop to sccp_server_run
add basic structure to sccp_session (WIP)
add sccp_queue data structure (WIP)
use sccp_queue structure in sccp_server
don't alloc mutex for config object
inject sccp_cfg to sccp_server submodule
remove close operation on sccp_queue