Connection check program for replica installation

When connection between a master machine and future replica is not
sane, the replica installation may fail unexpectedly with
inconvenient error messages. One common problem is misconfigured
firewall.

This patch adds a program ipa-replica-conncheck which tests the
connection using the following procedure:

1) Execute the on-replica check testing the connection to master
2) Open required ports on local machine
3) Ask user to run the on-master part of the check OR run it
   automatically:
     a) kinit to master as default admin user with given password
     b) run the on-master part using ssh
4) When master part is executed, it checks connection back to
   the replica and prints the check result

This program is run by ipa-replica-install as mandatory part. It
can, however, be skipped using --skip-conncheck option.
ipa-replica-install now requires password for admin user to run
the command on remote master.

https://fedorahosted.org/freeipa/ticket/1107

install/tools/Makefile.am

@@ -7,6 +7,7 @@ SUBDIRS = 			\
 sbin_SCRIPTS =			\
 	ipa-dns-install		\
 	ipa-server-install	\
+	ipa-replica-conncheck	\
 	ipa-replica-install	\
 	ipa-replica-prepare	\
 	ipa-replica-manage	\