Add functionnalities to switch between templateEngine and set custom binding attribute name

[quentinsup]

Hi,

Here two functionnalities with minor changes.

• Use multi-templateEngine

As it is only possible to have only one templateEngine, i've add a functionnality to define which templateEngine using a contentType description.

<script id="template-test" type="text/ko-template"> // use native templating </script>

<script id="template-test" type="text/jquery-tmpl"> // use jquery-tmpl </script>

<script id="template-test" type="text/custom-tmpl"> // use a custom templateEngine with "text/custom-tmpl" as contentType </script>

The way to set the global templateEngine is still the same (as jquery-tmpl autoset if exists)

• Personnalize data binding attribute name

As default knockout binding attribute name is 'data-bind', i've add a way to modify it and use another attribute name, through bindingProvider method

ko.bindingProvider.instance.setBindingAttributeName('data-app');

<input data-app="..." />

I'm waiting for your feedback !