djConfig should allow a list of modules to be auto-required

[alex]

it should be possible to load modules (particularly in simple pages) like this:

<script type="text/javascript" src="dojo/dojo.js"
    djConfig="require: ['dijit.dijit', 'dojo.dnd', ...]">
</script>

Or perhaps as:

<script type="text/javascript" src="dojo/dojo.js"
    djConfig="...",
    require="dijit.dijit', 'dojo.dnd', ...">
</script>

I don't really know which is better, but some form of attribute-driven auto-require seems intensely preferable to the current situation where most configuration can be handled via djConfig but a separate script block is required to do anything moderately interesting that requires non-Base modules.

For extra credit, the <script> tag that pulls in dojo.js should also support addOnLoad and addOnUnload properties, the values of which are converted to functions and pushed into the load handler stack.

[alex]

(In [10845]) fixes #4336