Added table comment tool tip for tables, listed in database structure page

Signed-off-by: Chanaka Indrajith <pe.chanaka.ck@gmail.com>
Merge remote branch 'upstream/master' into rfe_1462
Added rfe to changlog

Signed-off-by: Chanaka Indrajith <pe.chanaka.ck@gmail.com>
Merge pull request #816 from Chanaka/rfe_1462

Added table comment tool tip for database structure page