Feature: ~ uses ILIKE rather than LIKE

Using `~` on a query field (e.g. `name~`) will do a PostgreSQL `ILIKE`
query, though because of internetarchive/openlibrary#137
`_` will not work as expected.

infogami/infobase/dbstore.py

@@ -291,8 +291,11 @@ def process(c, ordering_func=None):
                     raise StopIteration
                 c.value = metadata.id
             if c.op == '~':
-                op = Literal('LIKE')
-                c.value = c.value.replace('*', '%').replace('_', r'\_')
+                op = Literal('ILIKE')
+                # Asterisks as part of the author's name query from patron input are escaped in Open Library
+                # so they don't become % wild card searches. E.g. an author styled as "Muñ*z" shouldn't have
+                # their "*" become a wild card. Other wild cards added by code should be converted to %, though.
+                c.value = r'\*'.join(part.replace('*', '%') for part in c.value.split(r'\*')).replace('_', r'\_')
             else:
                 op = Literal(c.op)