Code review minor fixes.

New operation '!' (insert) to box.update Lua fuction was added.

Conflicts:
	test/connector_c/update.c
	test/connector_c/update.result

connector/c update.test result was updated.

Review fixes:
  - Minor comments fixes;
  - INSERT operation behavior was changed: now INSERT operation was allowed
    under field next to last.
  - UPDATE connector/c tests was updated.

Actually, make the feature work.
Add syntax to Lua to be able to delete fields.
Fix a bug when we delete all fields in a tuple and happily
crash thereafter.

- INSERT AFTER operation was deleted;
- INSERT BEFORE was renamed to INSERT;
- Tarantool connector/c was updated;
- Tests was updated.

minor stylistic changes

Test's result files was fixed: 8-bytes string print as 64-bit integers.

box replications tests configurations files was updated. "slab_alloc_arena"
parameter was setted to 100 MiB.

Conflicts:
	test/box/lua.result

case

Set SO_KEEPALIVE option for replication replay sockets and fiber's clients
sockets.

Sorting result was added.

64-bit arithmetic and logical operations was added:
  - 32-bit fields can use 32-bit operands;
  - 64-bit fields can use 32-bit and 64-bit operands.