[boost] Logging library review is completed.

Hi, Thanks to everyone participating in the review of proposed logging library. I do believe this is one of the "must have" components to be included in boost libraries suite. Anyone who is interrested in sharing views on the subjust are still welcome (specifically I might be interrested in comparizon with other popular existing solutions). Nevertheless official tally is closed as of now and "jury is secluded for deliberations" ;). I'll try to compile the results within reasonable time frame. Genandiy Rozental - Review Manager -