Add patch file for the 'is_constitutive' patch, adding a column to the

exon table.

sql/patch_54_55_e.sql

+# patch_54_55_e.sql
+#
+# title: Add column 'is_constitutive' to the exon table.
+#
+# description:
+# The 'is_constitutive' column in the exon table will be set to true
+# for exons that are constitutive.  This is done by a script in
+# 'misc-scripts'.
+
+ALTER TABLE exon ADD COLUMN 'is_constitutive' BOOLEAN NOT NULL DEFAULT 0;
+
+# patch identifier
+INSERT INTO meta (species_id, meta_key, meta_value)
+VALUES (NULL, 'patch', 'patch_54_55_e.sql|add_is_constitutive_column');