some commands in tarantool shell

It would be nice if a user could:

1. use ';' symbol at the end of line (like mysql shell & postgresql shell)

example

 SELECT * FROM t1 where k1 = 10; SELECT * FROM t2 WHERE k2 = 20

2. repeat the last command and pass its output into pipe. I suggest to use '\g' command (like postgresql)

example:

 \g filename; - repeats last command and save its output into file
\g | grep abc; - repeats last command and write its output into pipe

3. support aliases for \g command