Add external_data column to protein_feature and dna_align_feature tables,...

 Add external_data column to protein_feature and dna_align_feature tables, primarily for storage of user-uploaded data.

sql/patch_50_51_e.sql

+# patch_50_51_e.sql
+#
+# title: Add external_data column to protein_feature and dna_align_feature.
+#
+# description:
+# Add external_data column to protein_feature and dna_align_feature tables, primarily for storage of user-uploaded data.
+
+ALTER TABLE protein_feature ADD COLUMN external_data TEXT;
+
+ALTER TABLE dna_align_feature ADD COLUMN external_data TEXT;
+
+# patch identifier
+INSERT INTO meta (meta_key, meta_value) VALUES ('patch', 'patch_50_51_e.sql|feature_external_data');
+
+