re #91 : Remove TemplateHelperInterface::setTemplate(). If no template if passed through the constructor lazy create a default template.
re #91 : Remove KTemplateFilterInterface::setTemplate(). If no template if passed through the constructor lazy create a default template.
re #91 : Make 'model' object property private
re #91 : Refactor KTemplate package

- Add KTemplateEngineInerface::isDebug() and setDebug() methods. If debug is enabled cache() method will throw exceptions if caching fails. If debug is disabled the method will return false. Debug config option can also be passed through the template engine factory.

- Remove KTemplateInterface::getContent() and toString() methods. KTemplateInterface::render() should always return a string.

- Rename KTemplateInterface::load() to loadFile()
- Rename KTemplateInterface::setContent() to loadString()

- Add KTemplateEngineMustache to support mustache syntax

- Add KTemplateExceptionSyntaxError. Throw syntax error exceptions when $this is used in templates.

- Implement partial support in mustache and twig engines and implement support for engine mixing through partials.

- Add KTemplateLocatorIdentifier::getLayout() to returna layout identifier from a template url.

- Add ComKoowaTemplateLocatorFile to handle file template overrides.
Synced with changes in framework