Cperello/haproxy api improvements

This improves the API to be able to understand it better. I reviewed it with quique. It doesn't change functionality, just clarifies the names.

I did the substitution with find and sed so nothing should be left without migration.

I used user corner suite to validate the changes:

	User Corner Test Suite
		InstallNonProfilePackages: OK
		EnableUsersZentyalTest: OK
		AddUser: OK
		Check-Login: OK
		Change-Password: OK
		Check-Login-failed: OK
		Check-Login-success: OK
		check-zentyal-log: OK
		check-syslog-apparmor: OK