Stringify process

Personnally, I support adding get_command (it was part of my initial issue!). The use case is when you want to retrieve all the command tokens for a command built with `pushargs()`. IMO, this makes the code cleaner: you don't have to create a local variable to build incrementally your command if you want to be able to use it later in your code. You can just use `pushargs()`and if you need to get the command tokens (as an array to avoid splitting them with the risk of splitting unproperly), you can just use `get_command`.