This is an wip patch for pgxc_ctl.   Now variable system and configuration
system seems to work fine.   Shell controller looks okay too.

Then I can write/test user command and operation, which still has many
things to do.
This commit removes some unneeded files.
This is 2nd WIP patch.   Now some of the important command works.
Still need tests for slaves.

Monitor shows starnge behaviour when issed "monitor all".   Need
to look into.

	modified:   Makefile
	modified:   config.c
	modified:   config.h
	modified:   coord_cmd.c
	modified:   coord_cmd.h
	modified:   datanode_cmd.c
	modified:   do_command.c
	modified:   do_shell.c
	modified:   gtm_cmd.c
	modified:   pgxc_ctl.c
	modified:   pgxc_ctl.h
	modified:   utils.c
	modified:   utils.h
	modified:   varnames.h