Add support for multiple inheritance (#1664)

* add all parent names

* clean up supportsInheritance

* fix npe

* fix allVars, fix test cases

* add more tests, remove comments

* update docker m2 cache dir, add more tests, fix mandatory

* update samples

* regenerate js spec files

* add logic to detect self reference

* add isSelfReference flag to codegen property

* add ruby tests for cat model

* remove debugging info

* fix JS allvars not have x-js-doctype

* update samples

* update js samples

samples/schema/petstore/mysql/mysql_schema.sql

@@ -95,9 +95,9 @@ CREATE TABLE IF NOT EXISTS `Capitalization` (
 --
 
 CREATE TABLE IF NOT EXISTS `Cat` (
-  `declawed` TINYINT(1) DEFAULT NULL,
   `className` TEXT NOT NULL,
-  `color` TEXT
+  `color` TEXT,
+  `declawed` TINYINT(1) DEFAULT NULL
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
 
 --
@@ -131,9 +131,9 @@ CREATE TABLE IF NOT EXISTS `Client` (
 --
 
 CREATE TABLE IF NOT EXISTS `Dog` (
-  `breed` TEXT DEFAULT NULL,
   `className` TEXT NOT NULL,
-  `color` TEXT
+  `color` TEXT,
+  `breed` TEXT DEFAULT NULL
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
 
 --