Implement syntax like:

create table t1 (x int) with system versioning partition by system_time;

which will create 1 history partition and 1 current partition.
Also it is possible to specify the number of history partitions:

create table t1 (x int) with system versioning partition by system_time partitions 5;

which will create 4 history partitions (and 1 current partition).

Tests:
partition.test cases are duplicated where it is appropriate for default partitions.
partition_rotation.test cases are replaced by default partitions where possible.