Parse SQLite "unsigned" and "short" noise words, fix #72.

In SQLite it's possible to define columns using type names such as
"smallint unsigned" or "short integer", without any changes to the way
those data types are handled, given its "dynamic typing" features.

Improve the pgloader casting machinery for SQLite to handle those cases.

src/sources/sqlite.lisp

@@ -16,14 +16,20 @@
 
 (defun cast (sqlite-type-name)
   "Return the PostgreSQL type name for a given SQLite type name."
-  (cond ((and (<= 8 (length sqlite-type-name))
-	      (string-equal sqlite-type-name "nvarchar" :end1 8)) "text")
+  (let* ((tokens (remove-if (lambda (token)
+                              (member token '("unsigned" "short")
+                                      :test #'string-equal))
+                            (sq:split-sequence #\Space sqlite-type-name)))
+         (sqlite-type-name (first tokens)))
+    (assert (= 1 (length tokens)))
+    (cond ((and (<= 8 (length sqlite-type-name))
+                (string-equal sqlite-type-name "nvarchar" :end1 8)) "text")
 
-	((string-equal sqlite-type-name "datetime") "timestamptz")
-        ((string-equal sqlite-type-name "double")   "double precision")
-        ((string-equal sqlite-type-name "blob")     "bytea")
+          ((string-equal sqlite-type-name "datetime") "timestamptz")
+          ((string-equal sqlite-type-name "double")   "double precision")
+          ((string-equal sqlite-type-name "blob")     "bytea")
 
-	(t sqlite-type-name)))
+          (t sqlite-type-name))))
 
 (defmethod format-pgsql-column ((col coldef) &key identifier-case)
   "Return a string representing the PostgreSQL column definition."