SAM format flag cases

paired end read가 mapping 되었을때,

• 163 (0x80,0x20,0x2,0x1) 과 83 (0x40,0x10,0x2,0x1)
• 99 (0x40,0x20,0x2,0x1) 과 147 (0x80,0x10,0x2,0x1)

paired end의 한쪽만 align 되었을 때

• 73 (0x40,0x8,0x1) 과 133 (0x80,0x4,0x1)
• 89 (0x40,0x10,0x8,0x1) 과 181 (0x80,0x20,0x10,0x4,0x1)