Removed practice of putting a datasync after every write, we now put a datasync around metablock writes.
Replaced boost::bind with std::bind in disk.cc.
Made metablock_manager used scoped_malloc_t in a place where it should.
Merge branch 'v1.6.x' into sam_520
Removed FILE_SYNC_TECHNIQUE define, since it is only used in disk.cc.
Removed unused header includes from disk.hpp.
Merge branch 'sam_520' into next
changing admin cli to attempt connection to localhost by default, as well as all --join options will use the default port if none is specified
fixing occasional crash due to sindex token not having been used when sindex post-construction is interrupted
Merge branch 'next' into sam_939_alt

Conflicts:
	src/arch/io/disk.cc
	src/arch/types.hpp
	src/containers/scoped.hpp
	src/serializer/log/data_block_manager.cc