change(format) format tables in output including their id

[Tieske]

This format changes the table serialization, by including the table id

Previous assert.are.equal({},{}) output:

Passed in:
(table) { }
Expected:
(table) { }

New assert.are.equal({},{}) output:

Passed in:
(table: 0x0fd935c8) { }
Expected:
(table: 0x0fd935a0) { }

This makes the message clearer when tables look the same but are not equal. Down side of this change is that the problem is shifted to the same assertion, which now becomes less clear.

Yet, because equal is more frequently used than same, this makes sense anyway.

[Tieske]

ping @ajacksified @DorianGray