Bring helper template specifications to more logical order
Add 'tags' to .gitignore
Changed the way kernel parameters are named

Send parameter name to functions that form
preamble/parameter declaration/expression
instead of component index and position.

This will allow to introduce recursive terminals
(terminals holding nested expressions), e.g.
vex::temporary from #50.
Provide optional prefix for kernel parameter names

refs #50
Send actual terminal to terminal processing functions

refs #50
Minor optimization of tagged_terminal code
Merge function declaration with preamble construction

refs #50
WIP: Unit test for temporary values

Is not working correctly yet. Needs temporary declaration step (local
preamble?)

refs #50
Working temporary terminals

refs #50
Got rid of unused parameter warnings