Added AdvisoryLock to have exclusive lock with blocking time
Set proper exception string

+ Real usage example in unit tests
Use a blocking lock to get iptables resource

On restart and stop to avoid other modules to get it
Use a blocking lock to get iptables resource

To avoid issues while firewall module is restarting
Depends on new core to get advisory lock
Enhanced EBox::Util::Lock instead of adding a new class
Adapt to use the new old class with arguments
Merge branch '3.2' into ejhernandez/race-condition-captive-portal

Conflicts:
	main/captiveportal/ChangeLog
	main/captiveportal/src/EBox/CaptiveDaemon.pm
	main/firewall/ChangeLog
	main/firewall/src/EBox/Firewall.pm
Fix typo
Added missing test dependency
Merge branch 'ejhernandez/race-condition-captive-portal' into 3.2

Conflicts:
	main/core/ChangeLog