Do not allow cartodbfying tables while no user quota is set

Closes #17
Updates tests

test/CDB_CartodbfyTableTest.sql

@@ -132,6 +132,8 @@ LANGUAGE 'plpgsql';
 
 -- table with single non-geometrical column
 CREATE TABLE t AS SELECT 1::int as a;
+SELECT CDB_CartodbfyTable('t'); -- should fail
+SELECT CDB_SetUserQuotaInBytes(0); -- Set user quota to infinite
 SELECT CDB_CartodbfyTableCheck('t', 'single non-geometrical column');
 DROP TABLE t;
 
@@ -171,3 +173,4 @@ DROP TABLE t;
 -- TODO: table with existing custom-triggered the_geom
 
 DROP FUNCTION CDB_CartodbfyTableCheck(regclass, text);
+DROP FUNCTION _CDB_UserQuotaInBytes();

test/CDB_CartodbfyTableTest_expect

@@ -1,6 +1,8 @@
 SET
 CREATE FUNCTION
 SELECT 1
+ERROR:  Please set user quota before cartodbfying tables.
+0
 single non-geometrical column cartodbfied fine
 DROP TABLE
 SELECT 1
@@ -24,3 +26,4 @@ trigger-protected the_geom cartodbfied fine
 extent|BOX(1 1,2 2)
 DROP TABLE
 DROP FUNCTION
+DROP FUNCTION

test/CDB_QuotaTest.sql

@@ -7,6 +7,7 @@ CREATE TRIGGER test_quota BEFORE UPDATE OR INSERT ON big
       EXECUTE PROCEDURE CDB_CheckQuota(1,1);
 INSERT INTO big VALUES (1); -- allowed, check runs before
 INSERT INTO big VALUES (1); -- disallowed, quota exceeds before
+SELECT CDB_SetUserQuotaInBytes(0);
 SELECT CDB_CartodbfyTable('big');
 INSERT INTO big SELECT generate_series(1,1024);
 SELECT CDB_SetUserQuotaInBytes(8);
@@ -15,3 +16,4 @@ SELECT CDB_SetUserQuotaInBytes(0);
 INSERT INTO big VALUES (1);
 DROP TABLE big;
 set client_min_messages to NOTICE;
+DROP FUNCTION _CDB_UserQuotaInBytes();

test/CDB_QuotaTest_expect

@@ -3,6 +3,7 @@ CREATE TABLE
 CREATE TRIGGER
 INSERT 0 1
 ERROR:  Quota exceeded by 3.9990234375KB
+0
 
 INSERT 0 1024
 0
@@ -11,3 +12,4 @@ ERROR:  Quota exceeded by 103.9921875KB
 INSERT 0 1
 DROP TABLE
 SET
+DROP FUNCTION