Logs should not contain PII

Description

Explicit log messages from CMS Core no longer contain Personally Identifiable Information (PII), like user name or IP addresses.

Examples of messages that should not container username. These have been found:
2018-02-06 13:28:14,723 [31] DEBUG EPiServer.DataAccess.Internal.ContentSaveDB: Saving content 5_5 (Action='641' User='admin')
2018-02-06 13:28:14,903 [31] DEBUG EPiServer.DataAccess.Internal.ContentSaveDB: Saved content 5_198 (Action='641' User='admin')
2018-02-06 13:32:04,804 [44] INFO EPiServer.DataAccess.Internal.ContentAclDB: 9.1.1 Access settings for contentID: 9 have been saved (non-recursive) by user: admin