Multilevel dojo-props support

Bug
---
Before this commit, ```data-dojo-props="constraints:{min:0}"``` doesn't work as
the current implementation support only one depth level of property.

Fix
---

We now use the eval function for the dojo-props attribute.
After this commit, the dojo-props must respect a valid form (as in vanilla dojo).

Eg:
	```	<select
		   		data-dojo-widget="dijit/form/FilteringSelect"
		   		data-dojo-props="name: 'filterSelect'; searchAttr: search">```

	now becomes:

	```	<select
		   		data-dojo-widget="dijit/form/FilteringSelect"
		   		data-dojo-props="name: 'filterSelect', searchAttr: 'search'">```