Templates can be applied at various nodes in the schema

[jsterne]

Requirements:

This requirement allows a template to be applied at any node in the schema. Although we should also allow for an implementation to have limitations/restrictions about which nodes can have an 'apply-template' (e.g. some implementations may only allow them on list nodes for example and maybe we shouldn't preclude that).

A corollary is that any node in the instance data has the possibility of having multiple template apply to that node (e.g. different templates could have been applied at multiple ancestor nodes). This works in combination with issue #1 (and would need precedence rules that take this requirement into account along with issue #1).