added support for cache group callbacks, closes #777. check out the ticket for details, guys, many of you will find this very useful
- documentation blocks
- some code cleanup
whitespace fix
whitespace changes
now uses the default context
- adds the assertContainerAttributeExists() method
- updates the sample apps tests
whitespace change
Merged revisions 2868 via svnmerge from 
http://svn.agavi.org/branches/1.0