Got rid of datum_t::operator*
Removed datum_t::operator->
Removed datum_t implicit conversion to bool
Fix typo in comment
Merge branch 'daniel_2985' into next
Merge commit 'baa9109cb1c25992443eb1705fa39479f4e9aeac' into reql_admin

(The commit being merged into reql_admin is the one that removed
the fake pointer datum interface from next. I merged it specifically
to keep the merge as small as possible and avoid including any other
changes in the merge.)

Conflicts:
	src/rdb_protocol/btree.cc
	src/rdb_protocol/store.cc