add template filling at run_tree clone time

[zippy]

this acts as a kind of dynamic macro substitution.

To do:

• mark processes (in their definitions) as templates (by adding to the process signature)
• allow passing of semantic map when "calling" a template process.
• check the process signature to make sure the template signature matches the passed semantic map

[zippy]

almost done as of 629ee7be271e which adds: -refactor of building run-trees to use semantic maps for template substitution -template signature to process definitions -semantic map to expectations so they can handle templated actions

Still to do:

• proper signature matching for the template signature. Code is in p_check_signature and should perhaps be broken out.

[zippy]

completed as of 2ae24ab4da5b