0.7: * Fix bugs that unexpected texts are displayed in group view mode * Fix bugs that columns are not displayed in the search dialog * Clean up code
0.6: * Fix the bug that the column handler is not added * Support version 13 and later * Change code to use addEventListener intead of the "oncommand" attribute to prevent vulnerabilities * Remove code using RDF, dropping support of version 2.0 or before * Fix a string to avoid a validator bug