This is pgxc_ctl commit for the initial feature.

Additional feature will be:
1) Add/remove coordinator/datanode,
2) Add/remove gtm_proxy
3) Add new gtm slave
4) Add new coordinator/datanode slaves --> Need to restart master
They will be added in later commits.

	modified:   Makefile
	modified:   bash_handler.c
	modified:   config.c
	modified:   coord_cmd.c
	modified:   datanode_cmd.c
	modified:   do_shell.c
	modified:   do_shell.h
	modified:   gtm_cmd.c
	modified:   gtm_util.h
	modified:   monitor.c
	deleted:    pgxc_ctl_bash.c
	modified:   pgxc_ctl_conf_part
	modified:   signature.h