Test multiple transactions in multiple blocks

[thepiwo]

Every transaction should be in the following block

• account A has 100 tokens, spends 100 to B should succeed
• account A has 100 tokens, spends 110 to B should be invalid
• account A has 100 tokens, spends 40 to B, and two times 30 to C should succeed
• account A has 100 tokens, spends 50 to B, and two times 30 to C, last transaction to C should be invalid, others be included
• account A has 100 tokens, spends 100 to B, B spends 100 to C should succeed