Made set_superblock_metainfo take a binary_blob_t to improve efficiency.
Made store_t::update_metainfo() more efficient by batching blob updates. Still somewhat bad though.
Inverted hash region intersection so it keeps large range regions, rather than large hash regions (which don't help us, because hash regions don't usually change while ranges change when resharding).
Make previous change compile
Merge branch 'v1.13.x' into daniel_2551_1