There's a few places where we can indicate read-only transactions to the Spring transaction wrappers. This removes the need for Hibernate to do a dirty check as part of it's "flush-if-necessary" check at the end of the transaction interceptor and improves performance.

Specifically, the following should be read-only:

• DAO transaction interceptor, get* methods
• PermissionManager interceptor, has* methods
• Plugin transaction interceptor, get* methods.

Additionally, get* methods on UserAccessor can be read-only except for ones that access property sets.