Move precharge and column mux cells to pgate directory.

Move gnd to M3 in column mux.
Create column mux cell unit test.

technology/scn3me_subm/mag_lib/sense_amp.mag

@@ -1,6 +1,6 @@
 magic
 tech scmos
-timestamp 1516827653
+timestamp 1523056564
 << nwell >>
 rect 0 0 40 102
 << pwell >>
@@ -50,13 +50,10 @@ rect 6 20 10 44
 rect 14 20 18 44
 rect 22 20 26 44
 rect 30 20 34 44
-<< nsubstratendiff >>
-rect 18 64 22 66
-rect 18 58 22 60
 << psubstratepcontact >>
-rect 32 138 36 142
+rect 32 137 36 141
 << nsubstratencontact >>
-rect 18 60 22 64
+rect 27 70 31 74
 << polysilicon >>
 rect 21 139 23 149
 rect 21 129 23 130
@@ -90,8 +87,7 @@ rect 29 51 33 55
 << metal1 >>
 rect -2 149 20 153
 rect 24 149 36 153
-rect -2 142 32 146
-rect 24 139 28 142
+rect 28 133 32 137
 rect 16 117 19 130
 rect 7 94 11 108
 rect 23 105 27 108
@@ -102,28 +98,25 @@ rect 15 78 19 80
 rect 23 94 27 101
 rect 23 78 27 80
 rect 15 75 18 78
-rect 15 72 21 75
+rect 15 74 31 75
+rect 15 72 27 74
 rect 7 65 9 69
-rect 18 66 21 72
-rect 18 64 22 66
-rect -2 60 18 62
-rect 22 60 36 62
-rect -2 58 36 60
 rect 6 44 9 54
 rect 33 51 34 55
 rect 31 44 34 51
 rect 3 20 6 23
 rect 3 15 7 20
 << m2contact >>
-rect 32 142 36 146
+rect 32 133 36 137
+rect 27 66 31 70
 rect 13 44 17 48
 rect 22 44 26 48
 rect 3 11 7 15
 << metal2 >>
 rect 10 48 14 163
 rect 20 48 24 163
-rect 32 146 36 163
-rect 32 138 36 142
+rect 32 129 36 133
+rect 27 62 31 66
 rect 10 44 13 48
 rect 20 44 22 48
 rect 3 8 7 11
@@ -140,12 +133,12 @@ rect 2 3 8 4
 << m3p >>
 rect 0 0 34 163
 << labels >>
-flabel metal1 0 58 0 58 4 FreeSans 26 0 0 0 vdd
 flabel metal1 0 149 0 149 4 FreeSans 26 0 0 0 en
-flabel metal1 0 142 0 142 4 FreeSans 26 0 0 0 gnd
 flabel metal2 10 0 10 0 4 FreeSans 26 0 0 0 bl
 flabel metal2 20 0 20 0 4 FreeSans 26 0 0 0 br
 flabel metal3 3 3 3 3 4 FreeSans 26 0 0 0 dout
+rlabel metal2 34 131 34 131 1 gnd
+rlabel metal2 29 64 29 64 1 vdd
 << properties >>
 string path 270.000 468.000 270.000 486.000 288.000 486.000 288.000 468.000 270.000 468.000 
 << end >>