Those messages are nothing to worry about. Repairing permissions is used for troubleshooting.
If can reset ACL's if you want > ACL found by repair permissions: Apple Support Communities
But better to leave it alone.
ACL stands for Access Control List and it is present on every file and folder you have on your computer. It is a list controlling who can access files and folders, and in what way.
Have a look here for more details: http://www.techrepublic.com/blog/apple-in-the-enterprise/introduction-to-os-x-ac cess-control-lists-acls/1048/
I suggest you repair disk permissions. Nothing bad can happen from repairing the permissions. Sometimes files need to be accessed by the system to perform certain functions. If the permissions on these files isn't correct, then problems might occur, even crashes of apps or services.