Roller session improvements

[snoopdave]

This PR enhances session security by properly invalidating user sessions when administrators change user attributes.

Key Changes

• Added RollerSessionManager to track and invalidate sessions
• Created UIBeanFactory to standardize Struts 2 bean creation
• Updated UserEdit to invalidate affected user sessions
• Added comprehensive test coverage

Implementation Details

• RollerSessionManager provides centralized session cache
• UIBeanFactory manages consistent bean creation across UI layer
• Extensive changes were needed to retrofit session management for proper dependency injection

[snoopdave]

I think this PR has gotten too complicated at I should revert it back to the first commit.

[snoopdave]

This PR works and might be considered an improvement, but I think this one is a better fix because it involves less changes: #148