[rubis] (change:major) Merged BrowseCategories and SearchItemsByCategories operations into a single BrowseCategories operation, since the latter is strongly related to the former.
[rubis] (chanage:major) Merged BrowseRegions and SearchItemsByRegion operation into a single BrowseRegions operation, since the latter is strongly related to the former one.
[rubis] (change:minor) Code clean-up.