Deprecate checkLogItemFormat

[phdmakk]

The !checkLogItemFormat check is only confusing and serving no real purpose as generally a user would be much more interested in the format of the complete log statement rather than individual log items within a log statement. In the simplest case a log statement consists of a single log item, but in such a case checking the log statement format covers the functionality of the check log item format. In addition its behavior deviates from the check log statement format behavior. Thus, it should be deprecated and eventually removed in future versions.