Makes spent time column available on the issue list (#971).
Rails3: model: replace deprecated validate method at watcher model
add unit test to validate watcher
Rails3: model: replace deprecated before_save method at UserPreference model
add unit test to ensure user preference others is hash in saving
Rails3: model: replace deprecated validate method at member_role model
add unit test of member_role validate
Adds tests for plugin API.
Removed unused method.
Adds a test for when accessing wiki history without permission.