Remove obsolete configuration

This pull request implements the changes suggested in #106:

* *`classExists`: If all classes should be guarded with if(!class_exists) statements.* This configuration seems to be from a time without autoloaders and uncontrolable includes. Besides it does not work with namespaces (see #96). It should no longer be necessary in 2014.
* *`createAccessors`: Create getter and setter methods for member variables.* In my opinion accessor creation should be default behavior. Properties should be declared `protected` as addressed in #88.
*  *`noTypeConstructor`: Do not generate constructor functions. The resulting code is functionally close to being a duplicate of the `constructorNull` The Makes all constructor arguments default to `null`*. If a argument is not nillable I think it should be required to set it in the constructor. Thus this configuration should no longer be used.
* *`noIncludes`: Do not add include_once statements for loading individual files*. Instead developers can use the new `autoload.php` containing an autoloader for the generated classes or use their own autoloader.
* *`prefix/suffix`: The prefix to use for the generated classes*. We have namespaces now. This configuration option should no longer be necessary.
* *`singleFile`: If the output should be a single file*. See prefix/suffix.