Sub-nodes should be compiled immediately by the Parser

[JohanDufau]

When a string like {node1 {node2 value}} is compiled by WTemplate, it will ignore {node2 value} and will trigger node1's compiler with {node2 value} as parameter.
Node1's compiler should trigger by itself a new parsing on the string recieved by parameter.

This should be done automatically by the Parser during the parsing phase.

1. Read node 1
2. Read {node2 value}
3. Trigger Node2's compiler with value as parameter
4. Trigger Node1's compiler with Node2's compiler result as parameter