Give support to custom actions without image

+ Those actions will not appear in the legend.
+ Added some devel doc to EBox::Types::MultiStateAction class
Update copyright end
Merge pull request #938 from Zentyal/ejhernandez/custom-actions-no-img

Give support to custom actions without image
Updated firewall to use the new haproxy API

Conflicts:
	main/firewall/ChangeLog
Added unit tests for EBox::Util::Version and added support for the new development schema version
Merge pull request #943 from Zentyal/cperello/haproxy-fixes

Cperello/haproxy fixes
Merge branch 'master' into jjmontes/trac-to-redmine

Conflicts:
	main/core/ChangeLog