Add first bits of value stack implementation, smaller improvements
Expand and refactor DSL infrastructure to support the most important value stack operations
Implement additional DSL tests
Fix
- bug at `Capture.render`
- bug at `toHList`

Implement
- first bits of `action` nodes
- extraction of types of a calling function
- passing arbitrary number of parameters to a function
Add `CalculatorDSLTest`
Fix `valueStack.mark` bug

Implement `Calculator` sample
Implement bunch of examples
- ABC
- Pascal nested comments
- Calculator that produces AST, that is interpreted afterward
Implement processing of anonymous functions that has underscored sections
Fix samples bugs
Implement `optional` and `JSonSimpleParser`
Add `value-stack` tests