Rewrote head (#1911)

See https://github.com/uutils/coreutils/pull/1911
for the details

tests/fixtures/head/lorem_ipsum_backwards_file.expected

@@ -0,0 +1,24 @@
+Lorem ipsum dolor sit amet,
+consectetur adipiscing elit.
+Nunc interdum suscipit sem vel ornare.
+Proin euismod,
+justo sed mollis dictum,
+eros urna ultricies augue,
+eu pharetra mi ex id ante.
+Duis convallis porttitor aliquam.
+Nunc vitae tincidunt ex.
+Suspendisse iaculis ligula ac diam consectetur lacinia.
+Donec vel velit dui.
+Etiam fringilla,
+dolor quis tempor vehicula,
+lacus turpis bibendum velit,
+et pellentesque elit odio a magna.
+Cras vulputate tortor non libero vehicula euismod.
+Aliquam tincidunt nisl eget enim cursus,
+viverra sagittis magna commodo.
+Cras rhoncus egestas leo nec blandit.
+Suspendisse potenti.
+Etiam ullamcorper leo vel lacus vestibulum,
+cursus semper eros efficitur.
+In hac habitasse platea dictumst.
+Phasellus scelerisque vehicula f

tests/fixtures/head/sequence

@@ -0,0 +1,100 @@
+1
+2
+3
+4
+5
+6
+7
+8
+9
+10
+11
+12
+13
+14
+15
+16
+17
+18
+19
+20
+21
+22
+23
+24
+25
+26
+27
+28
+29
+30
+31
+32
+33
+34
+35
+36
+37
+38
+39
+40
+41
+42
+43
+44
+45
+46
+47
+48
+49
+50
+51
+52
+53
+54
+55
+56
+57
+58
+59
+60
+61
+62
+63
+64
+65
+66
+67
+68
+69
+70
+71
+72
+73
+74
+75
+76
+77
+78
+79
+80
+81
+82
+83
+84
+85
+86
+87
+88
+89
+90
+91
+92
+93
+94
+95
+96
+97
+98
+99
+100

tests/fixtures/head/sequence.expected

@@ -0,0 +1,90 @@
+1
+2
+3
+4
+5
+6
+7
+8
+9
+10
+11
+12
+13
+14
+15
+16
+17
+18
+19
+20
+21
+22
+23
+24
+25
+26
+27
+28
+29
+30
+31
+32
+33
+34
+35
+36
+37
+38
+39
+40
+41
+42
+43
+44
+45
+46
+47
+48
+49
+50
+51
+52
+53
+54
+55
+56
+57
+58
+59
+60
+61
+62
+63
+64
+65
+66
+67
+68
+69
+70
+71
+72
+73
+74
+75
+76
+77
+78
+79
+80
+81
+82
+83
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+85
+86
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+89
+90