Fixed the "References" column

Now plural as in KiBoM.

kiplot/bom/columnlist.py

@@ -9,8 +9,7 @@ This is a class to hold the names of the fields and columns of the BoM.
 class ColumnList:
     """ A list of columns for the BoM """
     # Default columns (immutable)
-    # TODO: KiBoM uses Reference*s*, good for a column, bad for a field name.
-    COL_REFERENCE = 'Reference'
+    COL_REFERENCE = 'References'
     COL_REFERENCE_L = COL_REFERENCE.lower()
     COL_DESCRIPTION = 'Description'
     COL_DESCRIPTION_L = COL_DESCRIPTION.lower()
@@ -61,7 +60,7 @@ class ColumnList:
     # Default columns
     # These columns are 'immutable'
     COLUMNS_PROTECTED_L = {
-        COL_REFERENCE_L: 1,
+        COL_REFERENCE_L[:-1]: 1,  # The column is References and the field Reference
         COL_GRP_QUANTITY_L: 1,
         COL_VALUE_L: 1,
         COL_PART_L: 1,

tests/test_plot/test_int_bom.py

@@ -22,7 +22,7 @@ if prev_dir not in sys.path:
 # from kiplot.misc import (BOM_ERROR)
 
 BOM_DIR = 'BoM'
-REF_COLUMN_NAME = 'Reference'  # TODO make the same as KiBoM
+REF_COLUMN_NAME = 'References'
 QTY_COLUMN_NAME = 'Quantity Per PCB'
 KIBOM_TEST_HEAD = ['Component', 'Description', 'Part', REF_COLUMN_NAME, 'Value', 'Footprint', QTY_COLUMN_NAME, 'Datasheet',
                    'config']